640 Trow . — The Karyology of Saproleguia . 
What are these curious structures? As they make their 
appearance coincidently with the fatty reserve material of 
the oospore, and the fusions observed amongst them appear 
to coincide with the fusion of the oily globules, I think it is 
very probable that they have some connexion with the pro- 
duction of this reserve material. They take up all nuclear 
stains that I have experimented with more readily even than 
the chromosomes, and all my efforts to discriminate between 
them and the nuclei by differentiating staining failed. The 
only test by which they can be distinguished is that of 
structure, and as the structure of the nuclei, owing to the 
incomplete fixation, is not well seen in nearly ripe oospores, 
there is a great difficulty in distinguishing between the nuclei 
and some of the forms assumed by these bodies. As I have 
not tested them microchemically in the fresh condition nor 
paid any attention to them except in stained sections, I must 
refrain for the present from expressing any definite opinion 
as to their character and significance. For some time I worked 
on the assumption that they were analogous to the pyrenoids 
seen in so many of the Algae. It is not unlikely that they 
simply form a special part of the fatty globules, in other 
words are a special form of reserve material. It seems very 
probable that it was these bodies which led Dangeard to 
regard the ripe oospores as multinucleate ; this is all the 
more strange as he (’90 b) has described similar structures as 
occurring in the oospores of Cystopus Candidas. 
This study of the maturation of the oospores leaves the 
fusion of the gameto-nuclei undetermined, and it was mainly 
in consequence of this that I resolved, if possible, to follow 
the germination of the oospores. 
Germination of the oospores. Specially good cultures of 
5 . Thureti were obtained in September, 1894, and these were 
left in their jars for six months. In March, 1895, one of the 
cultures was removed to a warm room, the water changed 
and fresh flies added. The new flies were soon infected, and 
an examination of the old material then showed that many of 
the oospores were in all stages of germination. In germination, 
