76 
Chytridie. The growth here does not much exceed that required 
for the development of the new organisms, and the shape assumed 
is one entirely suited to the needs of the parasite. : 
It was the difference in this respect which first excited curiosity 
in the case of the Spirogyra cells in question. The organisms caus 
ing the hypertrophy were not easily noticed, while the manner of | 
growth suggested the normal development of root-like organs. = 
The first appearance of disease was that of separation between : 
the cells of a filament. Then the chlorophyll bands began to lose 
their hold on the wall, shrinking away from it, at the same time 
losing their closeness of coil until they become nearly parallel 
with the long axis of the cell. Although no measurements were 
taken, this probably came from the growth of the cell without the 
chlorophyll contents keeping pace with it. The whole proces 
lasted several weeks, and during all this time no traces of foreign 
organisms entering the cells of the Spzrogyra were found. This _ 
is, however, easily accounted for by the irregularity of the obsel- 
vations and the lack of any high powers of magnification. The 
later development was such as to suggest the probable presence of | 
certain monad forms which are known to prey upon different 5p*° : 
cies of Spirogyra, causing more or less disorganization and disease. 
If this were true, there were two very marked peculiarities ia : 
their development and results, differing from any account I have” 
been able to find in relation to the development history of pa 
little organisms. These are the singular distortion of the Spir- 
ogyra cells, before referred to, and the peculiar conduct of the 
monads after escaping from the cells, ) 
The first appearance of distortion was a lengthening of the 
wall on one side of the cell so as to produce almost a spiral OF 
This seldom occurred in a long filament, but generally in on€ _ 
one, two or three cells. From this bent or curved side of the 
cell was sent out a tube or branch, nearly at right angles with the 
long axis. This branch grew out more or less winding, tapering 
conically and often ended ina slight extension of a spherical shape 
Very often this tube branched dichotomously, the branches the? 
curling and twisting so they resembled small root-like appenda8™ 
so common to many Algz forms. Several short filaments were 
found, consisting of only three or four cells, coiled several time, 
