444 C. CLIFFORD DOBELL. 



forms may have the form of a broken filament, of an irregular 

 arrangement of branched filaments or chromatin masses, or 

 of an irregular network. So many different forms exist that 

 it is difficult to classify them accurately. 



On account of the large number oli intermediate forms, it 

 seems to me certain that all these different organisms are not 

 really different species. They grade into one another almost 

 imperceptibly, so that I regard the interpretation of them as 

 different species as excluded. Whether the spirogyra type 

 gives rise to the irregular type, and this in turn to the 

 flexilis type, or whether the process is in the reverse order, 

 cannot, of course, be stated with absolute certainty from an 

 examination of fixed and stained material alone. The former 

 interpretation, however, appears to me the more probable. 

 It is really immaterial which of these interpretations is 

 correct. The point of interest is that all these different 

 nuclear modifications occur in the same organisms. I shall 

 discuss the matter more fully later (see p. 471). 



This organism is, like typical spirogyra forms, niono- 

 sporic. The spore is formed towards — but not absolutely at 

 — one end of the cell (see fig. 14). I have not found all the 

 stages in spore-formation in my preparations, but such stages 

 as I have seen are similar to those of B. spirogyra. As in 

 this form also, the spore-forming individuals are short — 

 measuring on an average about 8 /u in length. A certain 

 amount of chromatin, also, is left over in the formation of 

 the spore (fig. 14). 



(2) Forms associated with B. saccobrauchi. — I have 

 already noted above (p. 441) that I found a number of smaller 

 Bacteria in my preparations of the blood of Saccobi-an chus. 

 These forms I will now describe. 



First of all, I should point out that although I found many 

 very small individuals, which were easily distinguished from 

 the large forms which I have called B. sac cob r an c hi, yet 

 many of the smaller forms were really but little smaller than 

 this form. Indeed, I found so many organisms of all sizes 

 intermediate between the larj^est B. saccobrauchi and the 



