Reproduction of Cystopus Ccindidus , Ldv. 3 1 7 
as the protoplasmic granules stain deeply. The nuclei possess 
a nuclear membrane, nucleolus and nuclear network, and are 
perhaps a trifle larger and more distinct than those in the 
mycelium. The protoplasm, both in the basidia and in the 
sporangia, stains deeply with all the ordinary nuclear stains. 
The formation of the zoogonidia has been described by 
Prevost (’07), De Bary (’63), and Btisgen (’82). 
Macallum’s observations (’95), already quoted, appear to 
accord very well with my own as to the distribution of 
stainable (iron-containing) substance. But I have been able 
to observe that the small chromatin-masses in the hyphae are 
the nucleoli of the nuclei. No figures are given by Macallum 
of the mycelia and haustoria, and it would be interesting to 
know whether the author had been observing the mycelia of 
P. parasitica , in which the nuclei are very rich in chromatin- 
substance and the haustoria very large, or the mycelia of 
C. Candidas , in which the nuclei do not contain so much 
chromatin and in which the haustoria are very small, as both 
fungi commonly occur on the same host-plant and the 
mycelium of one might be mistaken for that of the other. 
Formation of the Sexual Organs. 
The sexual organs, described by De Bary in 1863 , are 
found in considerable abundance in favourable specimens. It 
is impossible to say what induces their formation, or at what 
stage in the life-history of the fungus they appear, or under 
exactly what conditions. So far as I have been able to 
observe, a large supply of nutrient matter, such as occurs in 
the more succulent parts like the stem, is a general con- 
comitant of their appearance. It is not safe to trust too 
much to the abundance of the conidia on the surface of the 
stem, or to the decay of the stem, leaves, or fruits, as an 
indication of their occurrence. I have often found stems in 
an advanced state of decay, completely covered with the 
old basidia, to contain no sexual organs. On the other hand, 
