76 MORPHOLOGY OF THE BACTERIA. 
M. vaccine, Cohn (Microsphera Vaccine, Cohn). 
Very small micrococci, = 0.5 pw scarcely, iso- 
lated or united in pairs in recent vaccine virus 
and in the pus of variola pustules. By cultiva- 
tion, chaplets of from two to eight cells may be 
obtained, then masses containing sixteen to 
thirty-two cells of 10 » and more diameter. 
The M. of vaccine virus and of variola are 
identical, and Cohn regards them as different 
races of the same species. 
M. diphtheriticus, Cohn. 
Granular cells, ovoid, measuring from 0.55 to 
to 1.1 p, isolated or more often united in twos 
or in a chaplet of four to six cells; sometimes 
multiplying in colonies and extending them- 
selves in all the diseased tissues, decomposing 
and destroying them ((irtel). 
M. septicus, Cohn (IMicrosporon septicus, Klebs). 
Little rounded cells, of 0.5 », motionless and 
crowded in masses or united in chaplets, in the 
secretion of wounds in cases of septicemia 
(Klebs), in zoog/ea in callous ulcers, in isolated 
cells, united im pairs, or in chaplets in the se- 
rum of epidemic puerperal fever (Waldyer), in 
all the tissues, vessels, etc., in cases of pyemia 
and septicemia. 
M. bombycis, Cohn (Mycrozyma bombycis, Bé- 
champ). 
Cells with a diameter of 1 p, ordinarily united 
in chaplets of two, three, four, five, or more, in 
