430 C. CLIFFORD DOBELL. 



In the preparations of the contents of the large intestine 

 of Mabnia, I also found some small Bacteria which show a 

 similar structure. These forms (fig-. 41, PI. 16; fig. 76, PI. 17) 

 do not exceed about 10 /x in length, and are very slender. 

 Tliey all show a nucleus consisting of scattered granules of 

 chromatin during the vegetative existence of the organism. 



The Bacilli of the f lexilis type from frogs, toads, Lacerta, 

 and Mabuia all appear to have but one form of nucleus — 

 that of a diffuse system of chromidia. But in addition to 

 these forms, I have encountered two other organisms which 

 — whilst apparently belonging to the same group — present 

 certain features which separate them from the others. These 

 two org-anisms Avere found in the common Eno-lish newt and 

 the Naples lizard, but to my great regret my observations — 

 recorded in the ensuing pages — are very incomplete on both 

 of them. 



(4) Bacilli of a modified flexilis form from Triton 

 vulgaris and Lacerta muralis. 



(a) The form from Triton vulgaris. — I recorded iu a 

 previous paper (Dobell, 1908, p. 122) the fact that an organism 

 similar to B. flexilis occurs in the newt. Unfortunately it 

 is — as far as my observations go — exceedingly rare. I have 

 found it only once, inhabiting the large intestine of a T. 

 V u Igaris captured iu the vicinity of Cambridge. Subsequent 

 search for the organism in other newts has up to the present 

 been fruitless. 



The organism is very long and slender. It is also the 

 most flexible of all the flexilis forms which I have encoun- 

 tered. Many individuals attain a length of oO ft and more, 

 though the breadth is only about 1 ju. 



The living organisms were actively motile. They showed a 

 number of granules of various sizes in the cytoplasm, but no 

 other clearly visible structures. 



After fixation with formalin, and staining with Giemsa 

 (seep, 415), the organisms could be seen to have the following 

 structure (see figs. 79-82, 1^1. 17). Most of the cells pre- 

 sented a nuclear apparatus like thjit of B. flexilis (fig. 79); 



