1887. | BOTANICAL GAZETTE. 185, 
coast the stipes of the digitate Laminariz, while yet sub- 
merged, are attacked by a species of Sphzrella belonging to 
the Pyrenomycetes. 
Whether the filamentous and higher forms of parasites 
have been derived from the simple Chytridia is not easy to sur- 
mise. Among existing Chytridiacee we have a series of gen- 
€ra in some of which there are simple rhizoids, and in others, 
like Cladochytrium, a well-developed mycelium. Further- 
more, the species of, at least, three Cladochytria have lost the 
aquatic habit, and live in the tissues of Iris, Menyanthes and 
Sanicula. In Polyphagus, Nowakowski has also observed, 
a Conjugation of the mycelium of two individuals. Admit- 
ting the fugitive character of the mycelium of Chytridia- 
cee, there is still no reason why the filamentous fungi might 
not have developed from species of this order. The zodspore- 
bearing cells, as the parasite lost its aquatic habit and became 
aerial, might naturally be transformed into sporangia with 
hon-motile spores, like those of Mucor, and, as it acquired 
the power of growing in solid tissues, one of the conjugating 
cells would advantageously be developed into a pollinodium, 
and we should then find odsporic forms. But it is hardly 
Worth while continuing the chain of possibilities further in _ 
this direction. 
s I have said, it seems to me not unreasonable to suppose 
that true parasites may have originated at a very remote period 
Primarily from non-parasitic plants. But we must also consider 
