CONTRIBUTIOXS TO THE CYTOLOGY OF THE BACTEKIA. 459 



of Bacteria, the bacterioid forms — to distinguish them 

 from other forms. 



The other forms wliich this oi-ganism is able to assume 

 appeai-ed in the course of a few days in the contents of the 

 snake's large intestine, which had been kept as a culture in 

 a glass vessel. They were not found inhabiting the snake. 

 Multipb'cation of the bacterioid forms continued for several 

 days, after which the other forms made their appearance. 

 The oi-dinary bacterioid individuals (such as fig. 138, etc.) 

 were seen to become more rounded (fig. 142), finally assuming 

 the oval form characteristic of a yeast. In this yeast-like 

 condition the organisms continned to multiply — but by 

 budding, and not by transverse fission (see fig. 145). I 

 propose to call these yeast-like forms the zymoid forms — 

 to distinguish them from the rod-like bacterioid forms. 



The zymoid forms are exactly like any other ordinary yeast. 

 They possess an oval form, a vesicular nucleus, and repro- 

 duce by budding (cf. figs. 136 [PI. IS] and 145 [PI. 19]). 

 They are, indeed, exactly like other yeasts with Avhich I am 

 familiar in the rectal contents of frogs, toads, lizards and 

 many other animals. 



That the zymoid forms are directly derived fi'oin the bac- 

 terioid forms — and are not really independent oi'ganisms — I 

 can assert with absolute certainty. I have observed the 

 transformation in living organisms kept under observation for 

 several days. All intermediate forms, moreover, were found 

 in my fixed and stained preparations, and it was no un- 

 common thing to observe bacterioid and zymoid individuals 

 composing one and the same chain (fig. 151). Both l)ac- 

 terioid and zymoid forms existed side by side in my cultures 

 for many days, but finally the bacterioid foi-ms were almost 

 completely supplanted by the zymoid forms. 



Curious further changes were also observed. Many of the 

 bacterioid forms developed outgrowths, which sometimes 

 grew to a considerable length (see fig. 148). Many of the 

 zymoid forms also gave rise to outgrowths— in some cases of 

 very large size. These outgrowths began as short finger-like 



VOL. 56, PART 3. — NEW SERIES. 32 



