200 A Pathogenic Schhophyk of the Hog. [March, 



but in some respects even superior to a magnificent T V homoge- 

 neous immersion objective of Zeiss, which I was fortunate enough 

 to procure last spring. It, the Zeiss objective, is a trifle higher than 

 a &, These two objectives, the T V Tolles, and the T V Zeiss, have 

 been almost exclusively used during the last year. The T V of Tol- 

 les gives, with the No. 2 eyepiece, according to length of tube 

 and collar correction, from 1356 to 1525 diameters. 



The Swine-plague Schizophytes present themselves in three, 

 and probably in four, or even five, different forms. As to the three 

 different forms I am certain, as to the fourth and possibly fifth 

 I will not be so positive. The form to begin with is that of a 

 very minute spherical body, a micrococcus of o. 7 to o. 8 ft in 

 diameter. It is invariably present in the blood and blood serum, 

 in all morbid products and exudations, and in such morbid tis- 

 sues as can be conveniently examined with high power objectives 



o : o_ ^2_2 



r; 4, do. do. parting; 5, do. do. pasted joint with *U- 

 :<-; 7, blood corpuscles. X 1525 object- 



while fresh. It probably is not necessary to state that the micro- 

 cocci of Swine-plague, being spherical, do not present any char- 

 acteristic difference from other micrococci, occurring in other 

 substances, if the latter happen to be of about the same size as 

 the former. Still, differences can be observed, if the micrococci 

 are kept under the microscope for some time — a few hours — at a 

 suitable temperature. The Swine-plague micrococci soon form 

 'zooglcea-masses or aggregate in clusters and become imbed- 

 ded in an apparently viscous substance. While thus imbedded 

 they soon commence to duplicate by growing in two oppo- 

 site directions, and at the same time becoming contracted in 

 the middle. This contraction gradually becomes plainer and 

 plainer, and increases in the same degree in which the micro- 

 coccus is growing in length, till finally the latter presents the 



