3o8 TIMOTHY RICHARDS LEWIS. 



well-defined range of changes. Niigeli, as the result of his own 

 observations, declares that, of the three groups of fungi above 

 referred to, the " mould" and " sprout^' fungi are closely related, 

 but that, with one exception, they have not yet been seen to pass 

 from one form into the other. The exception consists in the cir- 

 cumstance that a certain species of mucor (a mould) has been 

 observed to present the two forms of vegetation — the filamentous 

 and the sprouting. Eission-fungi, however, do not stand in any 

 genetic relation to either of the other two groups, for they 

 neither give rise to other fungal forms nor originate from them; 

 hence it is distinctly laid down that they do not germinate. In 

 this it would appear that Niigeli and de Bary are completely in 

 accord. Niigeli states that it is comparatively easy to demon- 

 strate that the '' fission" group of fungi are not transformed into 

 other groups, from the circumstance that members of the latter, 

 when present in a solution, are killed at a lower temperature 

 than those of the former. This peculiarity, however, renders it 

 much more difficult to show that other (the "mould'' and 

 " sprout") groups do not give rise to schizom^cetes, as it is im- 

 possible so to isolate the germs of other fungi as to exclude this 

 group. Eventually, however, he was able to satisfy himself on 

 this point also by first destroying by heat all the fungal forms in 

 a nutrient solution, and then permitting a mould to extend its 

 filaments into it. In this way he kept some solutions thus pre- 

 pared for four years with only the " mould" form of vegetation 

 in them. 



Of the foregoing three groups of organisms the only one 

 which requires to be dealt with here is the third — the scJiizomy- 

 cetes — as it is only the various forms of this group of the fungal 

 family which have hitherto been unequivocally found in the 

 blood. 



Another distinguished botanist. Professor Cohn of Breslau, 

 has also paid much attention to these low forms of life, and has 

 recently devised a new system of classification for them, taking 

 as his starting-point the dictum that the schizomycetes are more 

 closely related to alga, than to fungi, and suggests, therefore, the 

 term schizophytce for the family, in place of the name given by 

 Nageli, which has been in general use hitherto. Cohn has, 

 moreover, advanced the supposed differences in physiological 

 properties manifested by some of these low growths as sufficient 

 grounds for assigning to them specific designations. In doing 

 this Nageli says Cohn has given expression to a generally enter- 

 tained opinion, and one especially aff'ected by the medical pro- 

 fession ; but he (Niigeh) is unacquainted with any facts in 

 support of such a view. " I have,'"" he writes, " during the 

 last ten years examined some thousands of difl'erent forms of 



