BRIEPFER ARTICLES: 
FERTILIZATION IN THE SAPROLEGNIALES. 
TRow! has reaffirmed his conviction that a sexual act is present in 
the water molds. His paper gives in detail the results of an investigation 
of Achlya DeBaryana and A. polyandra in comparison with my own study 
of oogenesis in Saprolegnia.2 Much of his paper is devoted to a defense 
of his earlier work and to cain criticisms of the skepticism of myself 
and others. 
A priori there is of course no reason why the Saprolegniales should not 
show examples of sexuality; the discussion has only been on the evidence 
that Trow presented in his paper of 1899.3 This evidence consisted in 
_| the varying number of nuclei present in the oosphere and oospore, expressed 
by Trow in the ratio 1:2:1, and certain figures of male gamete nuclei 
within the egg which did not seem to me clear enough to be convincing 
and appeared capablé&of other interpretations. I found that binucleate 
eggs, young and old, were “‘quite common” in an apandrous form of 
Saprolegnia mixta, and that by the methods of oogenesis bi- and trinucleate 
eggs might be expected in any of the Saprolegniales. Indeed all investi- 
gators of this group, HUMPHREY, Hartoc, and Trow himself, have known 
and described binucleate eggs. TRow in his last paper (p. 547) shite 
“in 
| to the binucleate eggs of my form as of ‘occasional occurrence” an 
all probability of a pathological character.’ I stated expressly that they 
were “quite common ” and I cannot see the slightest reason for suspecting 
them to be pathological. The cultures appeared perfectly healthy and the 
phenomenon was not infrequent as TRow implies. For these reasons I 
held that the number of nuclei in the ratio of 1:2:1, ordinarily accepted 
as evidence of fertilization when found successively in young and older 
stages of eggs and oospores, was insufficient for the establishment of sexu- 
ality in the Saprolegniales. To my mind proof is only furnished by clear 
and unmistakable instances of fusion between eggs and antheridial fila- 
ments and with thé male nuclei actually en route to the female at the point 
t Trow, A. H., On fertilization in the Saprolegnieae. Ann. Botany 18:541-560. 
pls. 34-36. 1904. 
2 Davis, B. M., Bor. Cuan: 35: aye 1903. 
3 Trow, A. H., Ann. Botany 13:131. 1899. 
1905] ‘ 61 
