DISEASES OF SWIXE AND OTHER ANIMALS. 11 



creases and becomes more lively if the rays of the light, thrown upon the 

 slide by the mirror, are sufficiently concentrated to increase the temper- 

 ature of the object. Another change observed by Dr. Dctmers, but the 

 cause of which he was not able to determine, was observed in the fact 

 that the globular bacteria or bacillus germs commence to bud or grow, 

 when, very suddenly, their further development ceases, and partially 

 developed bacilli and simple and budding germs congregate to colonies, 

 agglutinate to each other, and form larger or smaller irregularly-shaped 

 and apparently viscous clusters. These clusters are frequently found in 

 tlie blood and in other fluids, and invariably in the exudations of the lungs ; 

 and in the lymphatic glands in pulmonal exudation and in blood serum 

 this formation can be observed under the microscope if the object re- 

 mains unchanged for an hour or two. In the ulcerous tmnors on the in- 

 testinal mucous membrane but few of these clusters will be found, but 

 the fully-developed hadlliy many of which appear very lively, are always 

 exceedingly numerous. These tumors or morbid growths in the intes- 

 tines seem to afford the most favorable conditions for the growth and 

 development of the hacilli and their germs. The presence of such im- 

 mense numbers of these microphytes and their germs in the excrements 

 and other morbid products of swine leads Dr. Detmers to regard them, 

 beyond doubt, as the principal disseminators of the plague. Whether 

 these colonies or viscous clusters are instrumental in bringing about the 

 extensive embolism of the lungs and other tissues by merely closing the 

 capillary vessels in a mechanical way, or whether the presence, growth, 

 development, and propagation of the hacilli and their germs produce 

 pecidiar chemical changes in the comiwsition of the blood, thereby dis- 

 qualifying it from passing Mith facility through the ca]")illaries, or which 

 cause a clotting and retention of the same in the capillary system, Dr. 

 Detmers is not able positively to decide. He is of the opinion, however, 

 that these colonies or viscous clusters of bacillus germs and partially 

 developed bacilli cause sufficient obstruction of the capillaries to pro- 

 duce fatal embolism. 



The vitality of the bacilli and bacillus-germs is not very great, except 

 where preserved in a substance or fluid not easily subject to dccomi")osi- 

 tion ; for instance, in water which contains a slight admixture of organic 

 substances. Where contained in such a fluid and preserved in a vial 

 with a glass stoi)per, they will remain for at least five or six weeks in 

 nearly the same condition, or develop veiy slowly, according to the 

 amount of oxygen and degree of temperature maintained. In an open 

 vessel the development is a more rapid one. If oxygen is excluded, or 

 the amount available is exhausted, no further change takes place. In 

 the water of streamlets, brooks, ditches, ponds, «S:c., their vitality is re- 

 tained or preserved for some time. In fluids and substances subject to 

 imtrefactioii, they lose their vitality and arc destroyed in a companitively 

 brief period; at least they disappear as soon as those fluids and snb- 

 stances undergo decomposition. In tlie blood they disappear as soon 



