488 BOTANICAL GAZETTE [DECEMBER 
strictly diclinous, branched antheridia and the arrangement of the 
oogonia distinguish it markedly from that species. In A. DeBary- 
ana the oogonia are arranged in a loose raceme along the hyphae 
well out from the fly, while in A. Klebsiana the oogonia are always 
borne in a dense cluster near the body of the fly. 
Saprolegnia Kaufmanniana, n. sp. 
This species was collected from algal material in the botanical 
laboratory of the University of Michigan, of unknown source, but 
presumably from around Ann Arbor. 
Vegetative growth like that of S. ferax, with firm stiff hyphae; 
sporangia freely produced and of the same size and appearance as 
in S. ferax; gemmae round, oval, or irregular in shape, mostly 
single, sometimes in chains and freely produced; oogonia very large, 
on long or short stalks, or intercalary, scattered; oval or club- 
shaped, very rarely almost round, the usual size being about 
70-80 uX 100-2504. The smallest oogonium noted was 30X70 4; 
oogonium wall thin and smooth, without pits; oospores from 3 or 4 
in small oogonia to very many in large ones, averaging about 20-30 
oospores per Oogonium; oospores average about 30 pu in diameter, 
contents granular without any conspicuous oil drop; antheridia 
nearly always present, only occasionally absent on intercalary 
oogonia, diclinous, of various shapes from clavate to clasping or 
irregular, often curving part way round the oogonium, and borne 
on slender antheridial branches; usually more than one on an 
oogonium. 
This species seems to differ decidedly from all others described, 
especially in the large, thin-walled oogonia without pits. Rarely 
two oogonia were observed in series, as in fig. 5. This species may 
be related to S. anisospora, of which species little is known, though 
no evidence of two kinds of zoospores was found in the present 
species. Besides its marked morphological characters, S. Kauf- 
manniana is interesting from the fact that it is especially sensitive 
to the concentration of haemoglobin. Oogonia were but sparingly 
produced on flies, many cultures having none, and no culture having 
more than a few. Tests were made by transferring vigorous myce- 
lium to haemoglobin solution, and it was found that only where 
