SCIENCE. 



Cohn, Klebs, and others— who have attempted a classi- 

 fication are somewhat undecided themselves, and do not 

 agree where generic lines ought to be drawn. At any 

 rate, the Swine-plague Schizophytes do not fit into any of 

 the genera proposed. They are not bacteria, because 

 the single cells are spherical and not oblong ; they can 

 hardly be considered as Micrococci, because the same are 

 bi-spherical in their advanced stage of development ; and 

 they cannot be classed among the Bacilli on account of 

 their forming Zooglcea-masses. I have, therefore, pre- 

 ferred to use, for the present, that name, which, without 

 any serious contradiction, is given by modern investigators 

 to the whole family : Schizophytae or Schizophytes, or the 

 older name, introduced by Naegeli, Schizomycetes. 



The Swine-plague Schizophytes present themselves, ac- 

 cording to their stage of development, in three different 

 forms and shapes. Their simplest form, it seems, is that 

 of a Micrococcus, or of a small globule of about o. 7 or 

 o. 8 microm. Gutus inch) in diameter. It occurs invari- 

 ably in the blood, the morbid products, and exudations, 

 etc. of the diseased animals, and is never absent, but can 

 always be found, though in some cases in much greater 

 numbers than in others. The second form is bi-spher- 

 ical - the spherical cell having duplicated itself by a gradual 

 contraction in the middle, while growing endwise. These 

 bi-spherical Schizophytes are always more or less numer- 

 ous, and are motile, or move about, provided the temper- 

 ature of their vehicle — lung-exudation or blood-serum, 

 for instance — is not too low. Some of them, but prob- 

 ably only those, which, separated from a larger chain, as 

 will presently be explained, are provided, at any rate at 

 one end, with a fiagellum — a post-fiagellum — which, how- 

 ever, is so exceedingly fine that it can be seen only with 

 the very best high-power objectives, like a Tolles 1-15, 

 and the most favorable light obtainable, and even then 

 only while the Schizophyte is slowly moving. I have never 

 yet been able to see it while the Schizophyte is at rest. 



These double Micrococci, or bi-spherical Schizophytes, 

 soon undergo further development. Each single cell 

 soon again contracts in the middle while growing end- 

 wise, and, at the same time, separates more and more, 

 and becomes partially independent from its sister cell, 

 with which, however, it remains connected for some 

 time, even after it has completed its duplication. Mean- 

 while the sister-cell, too, has become bi-spherical, and 

 what a short while ago was a simple bi-spherical cell, has 

 become a double bi-spherical body, resembling a small 

 chain of four round joints. But the duplication does not 

 stop ; each of the four single cells, within a short time, 

 doubles pgain, and soon quite a little rod or filament will 

 be formed, which, on close inspection, presents a string 

 or chain of bi-spherical cells endways, loosely connected 

 with each other. Under moderately high powers — say 

 of 800 or 900 diameters — such a string presents a 

 slender, rod-shaped moniliform bacterium. While the 

 single cells, or each half of each bi-spherical body, soon 

 develop into double or bi-spherical cells, the connection 

 between the latter gradually loosens, so that finally, if 

 the temperature is not too low, and the development a 

 rapid one — I have frequently observed that the number 

 of bi-spherical cells in such a chain becomes doubled in 

 less than five minutes — the chain breaks up into smaller 

 ones (joints), each consisting of one or two bi-spherical 

 Schizophytes, which, in separating from their neighbors, 

 after some swinging to and fro, spin or draw out a very 

 slender thread, a fiagellum or cilium. But before all 

 these changes, this rapid duplication, take place, the 

 spherical Micrococci, when about to change to bi-spherical 

 bodies, form those clusters (Zobglcea or Coccoglia mas- 

 ses), which, being imbedded in,, or kept together by, an 

 apparently viscous substance, obstruct the capillaries, 

 and, according to my observations, constitute the prin- 

 cipal and direct cause of the morbid process. In these 

 Zoogloea-masses the single Micrococci, it seems, under- 

 go their first metamorphosis, or change to double bi-spher- 



ical cells, and this change continues, till portions of the 

 Zobgloea-mass separate, or till finally the glia breaks and 

 opens, when the bi-spherical bodies, and also some yet 

 unchanged spherical Micrococci, become free. The former, 

 very soon, commence their duplication, but as each new 

 cell or globule soon produces another one and becomes 

 bi-spherical, the same cannot be the source of lhe spher- 

 iral bodies or Micrococci. The latter, it appears, have 

 another origin, as will be presently explained. 



In Swine-plague material, such as blood, blood-serum, 

 lung-exudation, etc., if a day or two old, and sometimes 

 while yet fresh, bacteria of a peculiar shape and form 

 make their appearance. The same are rod-shaped, and 

 a trifle longer than a bi-spherical Schizophyte, or two 

 united spherical bcdies, but are not moniliform, and have 

 at one end, or in comparatively rare cases toward the 

 middle, a bright and light-refracting globule of much 

 more density than the rest of the bacterium. This glob- 

 ule is surrounded by a substance or an envelope of con- 

 siderably less density and is therefore less light-refract- 

 ing. If that globule is situated at one end of the bacter- 

 ium as is usually the case, the whole bacterium presents 

 the shape of a club, because the globule and its envelope 

 have much more diameter than the rod. Billroth calls 

 this form a Helobacterium, and the globule a lasting 

 spore (Dauerspcre). Such a lasting spore, according to 

 Billroth and Cohn, at any rate, if developed by a Bacil- 

 lus, is able to resist very high degrees of heat and cold, 

 and is very prolific, as it disseminates a large number of 

 germs, which, probably, constitute the source of the 

 globular bacteria or Micrococci. As such Helobacteria 

 are often found in perfectly fresh blood, and exudations, 

 etc. (in the exudations most frequently) of hogs, which 

 are affected with, or have died of Swine-plague, and are 

 nearly always seen if the blood and exudations, etc., are 

 a few days old, it appears probable that the same not only 

 constitute the source of the spherical bacteria or Micro- 

 cocci, but also that their great tenacity of life, or resisti- 

 bihty against adverse external influences, explains the 

 ability of the infectious principle of Swine-plague to re- 

 main effective for a whole year, if protected, by clinging 

 to, or being imbedded, in a moist and porous substance, 

 such as an old straw stack, etc. 



Whether or not Swine-plague-Schizophytes are able to 

 multiply in any other form and manner than stated, I 

 have not been able to observe. One observation, made 

 already at the beginning, has found new and repeated 

 confirmation, viz: wherever, or as soon as Bacterium 

 termo makes its appearance in large numbers, the Swine- 

 plague Schizophytes commence to disappear and disap- 

 pear in about the same ratio, in which the former are 

 increasing in numbers. In blood kept in a vial, Swine- 

 plague Schizophytes cannot be found when the blood 

 commences to exhibit a purplish color, or when the blood 

 corpuscles commence to decay, or become destroyed. 

 Further, the Swine-plague Schizophytes, although pre- 

 senting the same general characteristics when cultivated 

 in fluids foreign to the animal organism of a hog, show 

 differences in so far as the same present less uniformity 

 in size, and as this development and multiplication pro- 

 ceed slower, and with much less regularity. It seems 

 the cultivated Schizophytes change and develop slower, 

 and probably on that account are less vigorous in pro- 

 ducing mischief — at any rate, an inoculation with culti- 

 vated Swine-plague Schizophytes, although effective in 

 producing the disease, is always followed by a compara- 

 tively milder form of Swine- plague than an inoculation 

 with material directly from the body of a diseased hog. 

 This, however, does not involve that every inoculation 

 with cultivated Schizophytes produces under all circum- 

 stances a milder form of Swine-plague, than any natural 

 infection, for such is not the case. The difference may 

 be stated thus : A natural infection, or an inoculation 

 with material directly from the body of a diseased hog, 

 as a rule, produces a malignant and dangerous attack 



