Davis. — The Fertilization of Batrachospermu m. 69 
Fig. 37 is an example in which it has begun in both structures. 
In the specimen shown in Fig. 38 there was no prominent 
nucleus in the fused antherozoid, whilst there were two well- 
marked nuclei in the lower portion of the trichogyne ; but 
the presence of a number of darkly staining bodies in the 
antherozoid suggests the possibility of extensive division of 
its nucleus, while the basal position of the two nuclei in the 
trichogyne seems to be good evidence that they were once 
portions of the same structure. In this species also the old 
trichogynes and antherozoids attached to developing cystocarps 
frequently contained differentiated portions of the protoplasm 
that had a faint but definite greenish colour. The writer is 
compelled to consider them, at least morphologically, as true 
chromatophores, for they appear to be the remains of the 
chromatophores contained in the young trichogynes and 
antherozoids. 
Summary and Conclusions. 
The writer has reserved this portion of the paper for 
a consideration of the bearing of the observation just de- 
scribed upon the accepted idea of the structure of the 
procarps and of the process of fertilization in the genus. 
The problems involved in a satisfactory explanation of the 
process of fertilization are of great interest but very puzzling : 
we cannot, indeed, expect a solution of the questions until 
many more species have been studied in this genus and 
related forms. The number of species that the writer has 
examined is of course small, and they all come from the same 
locality. However, there is this to be said to their advantage, 
that each species represents a different sub-division of the 
genus as it has been considered by Sirodot. The sub- 
division Moniliformes is represented by B. monilifortne , that 
of the Helminthoides by B. Boryanum , and the Verts by 
B. coernlescens. The two extremes of the genus are thus 
represented : for B. moniliforme and B. coernlescens are types 
in which the procarps present the greatest differences in the 
size and form of the cells. 
