426 Campbell. — Studies on the 
primary prothallium, and one where apparently there is no 
interruption in its development. It is not quite clear from 
Miss Lyon’s account what is the history of the part of the 
spore-cavity below the prothallium. She states that the 
vacuole becomes filled with an emulsion and later with 
a semi-solid mass of granular matter, and that neither in the 
central nor basal part of the spore-cavity are nuclei present 
at any period of its development. It is impossible to determine 
from her figures whether any protoplasm is present in the 
lower part of the spore, as everything below the apical mass 
of cells is represented as absolutely similar ; it being impossible 
to say where the protoplasm (if any) ends, and the vacuole 
begins. Fig. 57 of her paper shows the whole spore-cavity 
to be ultimately filled with cellular tissue, which implies the 
presence of nuclei, thus contradicting the assertion that at no 
period are nuclei found in the central or basal part of the 
gametophyte. This raises the question, whether proper 
standing will not reveal the presence of nuclei in the basal 
part of the spore-cavity before the cell-formation begins. 
The Male Gametophyte. 
Miss Lyon’s account of the development of the male 
gametophyte and antheridium differs widely from that of 
previous investigators, especially Belajefif 1 . It cannot be 
said, however, that either her account or figures are quite 
convincing. From an examination of sections of the earlier 
stages in wS. Kraussiaiia there seemed little reason to doubt 
that the masses surrounding the groups of sperm-cells are, 
as they have every appearance of being and were interpreted 
by Belajeff, cells, and not mere structureless masses of food- 
stuff developed in vacuoles. Owing to the dense granules, 
which stain strongly and resemble nuclei, the presence of the 
latter, as in the later stages of the female gametophyte, is 
difficult to demonstrate, but in several instances what seemed 
to be undoubted nuclei were seen. The formation of the 
1 Antheridien und Spermatozoiden der heterosporen Lycopodiaceen. Bot. Zeit. 
43, 1885. 
