Capgrave was one of many who exaggerated the number of mortalities inflicted by the seemingly incomprehensible plague. Today it is known that plague among humans is caused by the introduction of the bacterium Yersina Pestis into the body. Research has also shown that the most common way a person can contract the disease is from a rat-borne parasite--the rat-flea.

The rat-flea, which was certainly the primary vector of the plague bacillus from rodent to man, was Xenopsylla cheopis. Although there are at least seventeen different species of rat-flea, X. cheopis is the most consistently capable of transmitting plague. The process of transmission from flea to man is in itself interesting and revealing. Y. pestis multiplies very rapidly in the blood of its rat host, resulting in massive septicemia. The flea, when feeding on such an infected rodent, ingests a large amount of plague bacillus. The bacterium, now maintained in the flea's stomach, multiplies rapidly until the flea's gullet is a solid mass of plague bacilli. "A rat-flea in this state is technically known as a "blocked" flea. (Shrewsbury, 2) At this juncture the flea becomes ravenously hungry, since no blood can enter its stomach. It then turns to any animal within close proximity for food, even man. The blocked flea will feed on human blood until its stomach is grossly distended, however, the recoil of its stomach walls causes it to regurgitate some of this blood, which contains masses of plague bacilli. (Ibid.)

Another act of great consequence is that while feeding the flea also defecates. The bacilli in its feces, deposited on the victim's skin, may then be forced into the wound when the bite begins to itch and is scratched. Almost at once, upon the death of a plague-rat and the subsequent chilling of its corpse, the fleas it has carried leave to seek new hosts. In a human habitation the most natural new host is man. Man is often the only possible living host, although the fleas will also attack cats, dogs and livestock. (Ibid)

Under control conditions of temperature and humidity, blocked fleas can remain alive for at least six weeks. However, their ability to transmit plague does not usually exceed two weeks. Bubonic plague in Europe occurred seasonally, since the optimum temperature for reproduction of X. cheopis is 60° to 85° Fahrenheit, accompanied by low humidity (Hirst, 262). Favorable breeding weather could produce much greater numbers of plague fleas within a month, resulting in an epizootic outbreak of plague among the rodent population. Extremes of heat or drought, cold or humidity could severely check an eruption of bubonic plague. Because of this critical climatic factor, outbreaks of this form of plague in England usually occurred in late summer or early autumn and subsided suddenly with the coming of the first frost. During the winter the disease lay dormant. (Shrewsbury, 3)

There are two distinguishable species of rats which have been or are indigenous to the British Isles. The first is Rattus rattus. R. rattus is the black rat, a house or ship rat. The second species is Rattus norvegicus, or brown rat. R. norvegicus is commonly known as the field or sewer rat. The choice of habitation by these two rat species is of cardinal importance when dealing with bubonic plague. The black rat is a burrowing animal whose favorite habitat is in the walls, eves, ceilings or roofs of human dwellings. The black rat is smaller and more timid than the field rat, is a good climber but is less muscular than the brown rat. R. rattus is usually a non-migratory animal except during times of famine and when he is bodily displaced--possibly in the transport of goods. These qualities, distinguishing the black rat from the brown rat, make R. rattus an ideal carrier in the man-rat-flea relationship. (Shrewsbury, 7)

The man-rat-flea relationship is so important in regard to the spread of Y. pestis that the existence or non-existence of the black rat in a given geographical area is often the deciding factor in determining if a reported disease or pestilence was in fact plague. Since there is no doubt that bubonic plague was in evidence in the 1348-1350 outbreak, R. rattus must have existed in multitudes in England even though there is only circumstantial evidence of his presence. (Ibid.) The first instance of the depiction of a rat in the literature of the British Isles is in The Book of Kells (Henry, 107). An illustration in that book depicts two rats nibbling a host under the watchful eyes of two cats. J. F. D. Shrewsbury has questioned the existence of the rat in Europe prior to the crusades. His argument affirms the presence of early skeletal remains in Italy, but counters by pointing out that neither the Greeks nor the Romans had a specific designation for rat. (Shrewsbury, 9-11) This argument is countered by evidence of skeletal remains from Pompeii, bronze statuettes found in Rome--one of R. rattus and one of R. norvegicus--both dating from the first century A. D. It is further asserted that in Spain in the first century of this era the word mures was used to denote mouse as well as rat, and muricides were used during one pestilential incidence. Avicenna, 980-1037, noted a relationship between plague and dead rats in Spain. (Morris, 213) This argument may seem too overdrawn for a study of this scope, however, in order for there to have been as great a mortality as is claimed for the fourteenth century pandemic, the black rat would have had to arrive on the scene at an early date since he is timid and not prone to travel. (Shrewsbury, 11-13)

Plague bacilli were first seen and identified by microscopic analysis in Hong Rong in 1894 by a Japanese, Shiramiro Kitasato, and a Swiss, Alexander Yersin. (Hirst, 106-111) It was only after that time that positive measures could be undertaken for a cure of the disease. The level of medical science in the fourteenth-century, as we have seen, was totally inadequate to cope with any microbial disease. Plague, however, does not manifest itself by only one set of symptoms. It can take on at least three major forms of infection--bubonic, pneumonic and septicemic.

Bubonic plague is the most common form of the disease. Its most obvious symptom is the formation of the bubo, a hard painful swelling of a lymphatic gland nearest the area of the flea bite. A bubo can appear on the neck, under the arm or in the groin. The plague bubo is recognizable on the first day of infection and is quite prominent from the second to the fifth day. Boccaccio described this symptom. (Boccaccio, xxiv)

Bubonic plague is a very painful disease. The onset is usually abrupt, accompanied by severe headaches, high fever, vomiting and chills. Speaking becomes difficult, hearing is impaired and the eyes are suffused. Mobility is nearly impossible. (Bower and Pilant, 390) If the infected individual should live beyond the fifth day there was the possibility that his buboes would suppurate and recovery follow. To endure this was a painful prospect. (Shrewsbury, 5)

During an outbreak the percentage of mortality usually varies from a possible ninety per-cent of those infected at the onset, to as low as thirty per-cent of those infected as the epidemic subsides. This is due to a varying degree of virulence inherent in any bacterial disease. The probable average case mortality of bubonic plague is sixty per-cent. (Ibid.)

The most contagious form of plague is certainly the pneumonic. This is probably the most deadly bacterial disease known to man. Primary pneumonic plague is a disease of cold climates, and thus is a grave danger during the winter months rather than in the summer. Pulmonary plague spreads directly from man to man, independent of the man-rat-flea relationship. Plague pneumonia causes severe coughing and spitting of bloody sputum. The airborne bacilli, when inhaled, cause further spread of the disease. Logically, the winter months are the best time for the spread of this form of plague, since humans would tend to stay closer together as a means of keeping warm. This was certainly the case in the fourteenth century. The relatively cramped conditions in peasants' dwellings would only serve to increase the probability of the spread of contagion. (Hirst, 221)

Death, in cases of pneumonic plague, is usually sudden as a result of heart failure. The victim invariably does not live more than four days after the appearance of symptoms. Case mortality is usually one hundred per-cent (Shrewsbury, 6). Intensive studies in Europe and Asia have still not revealed the exact cause for the initiation of outbreaks of pulmonary plague, although theories abound, pneumonic plague seldom develops independently of the bubonic form, but there have been instances of totally pneumonic epidemics. (Hirst, 220-231)

Guy de Chauliac recorded vividly the duration and symptoms of both bubonic and pneumonic plague. (Ziegler, 19)

The third important form of plague is the septicemia. When plague septicemia develops, the weight of infection falls on the blood stream. Infection is caused by the rat-flea as in bubonic plague. Septicemia plague is extremely acute. The victim may die suddenly within a few hours of initial infection and complaint of illness. Buboes have no time to form. "At autopsy, the blood and all the tissues are found to swarm with plague bacilli. . .yet there may be singularly few physical signs visible to the naked eye." (Hirst, 29) Cases of septicemia plague must have occurred in the fourteenth-cen-tury, since there are accounts of people who died overnight, having gone to bed in perfect health. It is also related that priests, while administering last rites over a plague victim, suddenly died before the person to which they were ministering. (Ziegler, 19)

Plague found adequate means to spread throughout England. Roads were in good repair and the network, by the fourteenth century, was greater than in Roman days. This was necessary to facilitate the growth in overseas trade. Blocked fleas could easily travel in bales of wool or in grain shipments. Fairs and places of pilgrimage provided points for transmission of plague. Dwellings of the time provided hospitable quarters for the plague-rat and flea. The most common building materials were wattle-and-daub, cob, or earth and mud. Some cottages were roofed with wooden shingles, but most were thatched with straw. The floor of the average dwelling was hard beaten earth, while beds were made of wooden frames laid with straw. Dwellings were smoky, humid and dark, with usually no more than two rooms. Generally one room was used for living purposes. This included shelter for domestic animals as well as humans. The other room was for communal sleeping. Inhabitants usually slept naked or in the same clothes they had worn all day, depending on the temperature. (Coulton, 311) It can be observed that the medieval dwelling provided ideal conditions for the comfort of the black rat and spread of plague.

There has been recent controversy over the nature of the Black Death. J. F. D. Shrewsbury paints a picture of the Black Death as a purely bubonic epidemic which could not have killed more than a twentieth of the English populace. (Shrewsbury, 123) He interprets as 'typhus' those accounts, which would appear to support the contention that there was a pneumonic infestation. Christopher Morris points out in his critique of Shrewsbury's book that the symptoms of typhus are discernable from pneu-monic plague. When one reads of deaths within three days accompanied by the spitting of blood, typhus being an illness of greater duration, there can be no such conclusion as that of Shrewsbury. (Morris, 208) Greenwood states that plague in Europe seemed to "change as the season of the year changed from pneumonic to bubonic, and then from bubonic to pneumonic without discontinuity (Greenwood, 308)." Eruptions of plague were often accompanied by outbreaks of typhus, smallpox, measles and dysentery, (Shrewsbury, 127) but since the etiology of plague is not invariable, (Morris, 209) the Greenwood thesis seems the most credible.

The plague, after leaving devastation in its wake, did not entirely disappear. Although new strains of bacilli were probably introduced into England, thus causing severe recurrences of this disease, it is not entirely impossible to side with those who assert that plague became endemic in England after 1348 (Mullet, 210). In any case, there were further instances of plague in England in 1361-1362, 1369, 1375 and 1390, to list only the national recurrences and, in addition, during the same period, there were many severe local outbreaks. (Bean, 427-429)

When dealing with the subject of the Black Death, the problem of population and its decline is one which must be dealt with in order to have some firm basis for understanding the enormity of the force which was to change the face and character of England. In this instance the data left for us in the chronicles and records of the time are inadequate. Few contemporary sources estimate the loss of life to have been less than fifty per-cent of the populace. "Enough cases have been established where the estimates of the chroniclers were palpably impossible to despel any lingering belief that the man on the spot knew best." (Ziegler, 227)

The point at which England began to experience her demographic decline is disputed, and, when dealing with plague, one must take into consideration the effects of later pest-ilential visitations. The demographic decline may go back to the beginning of the fourteenth century or earlier (Postan, 570). In 1315-1316 England experienced a severe famine. In 1348-1349 the Black Death ravaged the land. In 1361-1362, 1368-1369 and 1375, plague, as well as other infectious diseases, reached epidemic proportions (Greenwood, 291). The population figures for the beginning of the fourteenth century cannot be established with anything approaching certainty, but the thesis that the population of England increased between the eleventh and fourteenth centuries is generally accepted in spite of only circumstantial verification (Postan, 563). Therefore, it is postulated, Sometime in the intervening years between 1300 and 1348 the English population achieved its highest level of the Middle Ages (Russell, 1966, 1). From the first definite reckoning of the size of the English populace--the Doomsday Book of 1086, from which it is is estimated to have been from 1,250,000 to 1,500,000--to the poll-tax returns of 1377, there exists nothing which could be used to provide even a general estimate. (McKisack, 312)

There are divergent opinions concerning the population apogee during the fourteenth century. One of these opinions is that the population gradually rose to a peak of 3,700,000 in 1348, at which time "the agricultural people were being crowded. (Russell, 1948, 314 & 280) Another opinion hypothetically states that medieval English population leveled off about 1315, then began to drop due to famine and pestilence at that time. The population, according to this thesis, continued to decline only to be stimulated to growth for a few years prior to the Black Death, but did not recover sufficiently to equal the population level which existed before 1315 (Postan, 39-43). Proponents of this theory believe that English population could have been far denser than Russell's 3,700,000, reaching six to eight million. (Ibid.)

The arguments are compelling, and it is difficult to do anything but acknowledge the effort put into arriving at some sort of solution. This effort is not useless as is sometimes indicated by certain authors. (Ziegler, 227) The work of J. C. Russell is undoubtedly the most lengthy and exhaustive in this field. Although it is difficult for this writer to wholly accept or fully understand all of his calculations, they are of great interest. Russell bases his totals of medieval population on the Doomsday records and the poll tax figures of 1377, as well as English inquisitions post mortem as a basis for inquiry. Then, by calculating life expectancies, estimating sex ratios, projecting recovery rates, and computing the average size of a medieval household, among other devices, he has been able to offer a projection of the population of medieval England. The bases of arguments against his approach has been to point out the inexactness of the records and the prevalence of evasions. Also ques-tioned is Russell' s calculation that the average family size was 3.5 persons. It has been pointed out that the numbers comprising the family unit could have been greater, and that such deviation, when added in, could increase the estimate of population to over four million in 1348. (Postan, 41) Russell believes that approximately twenty per-cent of the inhabitants of England perished during the Black Death, while Postan would place the figure at a third or even higher, possibly forty per-cent. (Ibid., 33-34)

Professor Shrewsbury has postulated another theory concerning the mortality of the Black Death. He first calculates the population of England by using the inexact method of averaging all well-known estimates of the population level of 1347. (Shrewsbury, 23) The figure he arrives at is four million for the preplague populace. Shrewsbury states emphatically that the Black Death must be reviewed dispassionately. (Ibid., 123)

It does seem evident that Shrewsbury is misrepresenting events after the Black Death. Although it was the cumulative effect of successive national epidemics, which caused the most lasting change, it hardly seems the case that there were no deserted villages, no interruption of agriculture and no appreciable change in the manner and customs of the English. It has already been demonstrated that the fourteenth century pandemic contained both pneumonic and bubonic elements; it will now be shown, in brief, since a more extensive survey will be presented in the next chapter, that the consequences do point to a death toll more in line with the figures of Professors Russell and Postan.

While there was no wholesale depopulation of villages after the Black Death, and the role of disease in the fourteenth century as a diabolus ex machina has to be avoided, there are outstanding examples of villages which ceased to exist because of the plague in the mid-fourteenth century. (McKisack, 332) Standelf and Tilgarsley were two such villages. Both were located in Oxfordshire. In Standelf, the incumbent priest of Pyrton petitioned his archdeacon to be relieved of the duty of saying regular services in the chapel there "since the hamlet had no more villagers after pestilentia et ipidemia."(Beresford, 159-160, 382) Tilgarsley presented a similar problem. "In 1359 they re-ported to the Exchequer that no one had lived there since 1350 and they could not collect the 94s. 9d. tax." (Ibid., 160, 382)

To say that there was no interruption of land tenure seems to be a statement meaning that the manorial system itself did not collapse because of the Black Death (Bean, 8-10). This is conceded. The manorial system was in a state of decline which was aggravated severely by the plague, but the system certainly did not collapse entirely between 1348 and 1350. However, the interruption of normality in the agricultural realm is well documented by Henry Knighten. (Myers, 61-62)

It is also worth noting that Knighten goes on to describe the great surplus of all types of goods resulting from the high mortality and consequent reduction in demand and market value of merchandise. He rounds out this picture with a statement concerning the higher wages demanded by laborers for their services due to shortages of workmen after the pestilence.

Any argument concerning an 'appreciable' change in anything would require a definition of the term as it is applied to the case in point. The manners and customs of English life were obviously affected. The manorial system began disintegrating at a more rapid pace. Commutation of labor services for money payments, though not uncustomary, became more the rule than an exception. "Clerks became mer-chants, former workmen became employers and contractors, farm laborers became gentlemen farmers." (Thompson, 568) A stepped-up revolution in agriculture and increased social mobility do not appear to be unappreciable changes.

There has been another means suggested which might also shed some direct light on the plague casualty level. This method is the study of deaths recorded in ecclesiastical registers. The clergy regularly kept records of all deaths within their ranks. The mortality among the beneficed clergy presents a graver picture of the effects of plague. The death rate in York was 39 per-cent, Lichfield 39.6 per-cent, Bath and Wells 47.6 per-cent, Ely 48.8 per-cent and 48.8 per-cent for Norwich, Winchester and Exeter; death totals in the monastic community tended to parallel the same percentages. (Ziegler, 228)

It would appear that the mortality among the clergy was greater than that among the general populace. It is possible that their ministrations to the dying put them in greater danger of infection, or it could mean that these figures show a clearer picture of the actual death toll. The relevancy of clerical deaths to the actual mortality is still undetermined.

It is probable that no exact figure will ever be determined which will satisfy all parties concerned with the percentage of deaths due to plague in the years following 1347. The consensus would appear to be, Shrewsbury notwith-standing, that from twenty to forty per-cent of the population was eliminated by the Black Death. This formidable estimate is merely a brief preview of the widespread effects of this terrible calamity.