1898] BRIEFER ARTICLES 431 
of the division walls, such as M. Gayet seems to have considered super- 
fluous, is very essential. 
In studying M. Gayet’s technique it is evident that he has depended 
too much upon rather primitive methods. While he has had recourse to 
various fixing and staining agents, he admits that so far as possible he 
has depended upon free-hand sections or “dissociation,” 2. ¢., the dis- 
section with needles of material treated with a strong macerating 
fluid. Where objects were too small to be thus handled they were 
imbedded in celloidin, which was then included in a coating of 
glycerine-soap. He does not appear to have employed paraffin for 
imbedding, nor to have employed any but nuclear stains, and it is 
very evident from some of his figures, ¢. g., 5, 83, that cell-walls were in 
some instances entirely overlooked. In my own studies of the arche- 
gonium I have found such thin serial sections as can most readily be 
made by the paraffin method indispensable, and some good stain for 
the cell-walls, like Bismarck-brown, is necessary in order to differ- 
entiate the young cell-walls. The doubtfulness of conclusions drawn 
from a study of optical sections alone, from material rendered trans- 
parent by potash or other clearing agents, need not be insisted on 
here. 
In short, until some of the statements made by M. Gayet can be 
confirmed by a thorough study of properly stained serial microtome 
sections, his conclusions can hardly be accepted without a certain 
amount of reservation Doucitas HouGHToN CAMPBELL, Leland 
Stanford Junior University. 
THE HOMOLOGY OF THE BLEPHAROPLAST. 
rmatozoids have not only 
THE recent investigations upon plant spe 
development 
added immensely to our knowledge of the structure and 
of these organisms, but have brought out interesting suggestions as to 
the homologies of certain structures. no ce : 
Previous to 1894, writers were concerned largely in discussing 
whether the body of the spermatozoid consisted of anomie orate or 
of both nucleus and cytoplasm. All agreed that the cilia are dev 
from the plasma. Later contributors, Belajeff, Hirasé, Ikeno, We ee: 
Shaw and Fujii, have shown conclusively that the body of the mature 
Spermatozoid consists of both nucleus and cytoplasm ; and, further, 
