454 C. CLIFFORD DOBELL. 



their large intestines. They appear to be the same in both 

 hosts, but I have found them more often in the toad than in 

 the frog. Many of them, however, are of very small size, so 

 that they are easily overlooked unless one is specially on the 

 look-out for them. 



As a rule these organisms occur in the double form (fig. 

 115) — single spindles being comparatively rare in any prepara- 

 tions. The ends of the double spindles are more rounded 

 than in the forms from the lizard. The nuclei are of the 

 same type. Fig. 115 is an individual (double) from the large 

 intestine of Bufo vulgaris (moist film, sublimate-alcohol 

 and Heidenhain). Heidenhain and Giemsa reveal the same 

 structure. The length of the double individual depicted in 

 this figure was ca. 10^. 



(c) "Fusiform Bacteria" from Triton vulgaris. 



The common newt contains several different forms of fusi- 

 form organism. They are similar to those of the frog and lizard, 

 and usually occur in the double form. I have not made a 

 very careful study of these organisms, but they show certain 

 features of interest. 



Each individual (figs. 66, 67, PI. 17), contains a single 

 nucleus. This may take the form of a simple, apparently 

 solid granule of chromatin (cf. fig. 07, upper nucleus), or 

 occasionally it appears to be a vesicular structure with one 

 large karyosome (cf. fig. 67, lower nucleus). From the 

 small size of these nuclei it is often very difficult to be 

 quite certain of their exact structure. Another type of 

 nucleus, which I observed in some of the larger forms from 

 the newt, is that shown in fig. 66. This figure shows an 

 ordinary double form in which the upper individual is 

 dividing into two. It will be seen that all three nuclei which 

 are present are in the form of double granules, arranged 

 transversely across the cells. All these forms were seen in 

 Giemsa preparations, which were fixed with formalin, and 

 dried before mounting. It is therefore not impossible that 



