SUMMARY OF CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally invertebrata and cryptogamia), 
MICROSCOPY, Etc. 
Including Original Communications from Fellows and Others .* * * § 
ZOOLOGY. 
VERTEBRATA Embryology, Histology, and General. 
a . Embryology. f 
Sedgwick’s Theory of the Embryonic Phase of Ontogeny as an 
aid to Phylogenetic Theory 4 — Mr. E. W. MacBride does not discuss 
the correctness of Mr. Sedgwick’s views as expressed in his essay pub- 
lished last year,§ but rather, assuming them to be true, points out some 
of their consequences. These may be summed up thus : — the earliest 
well-marked larval stage which has been discovered is the blastula, a 
sphere of uniformly ciliated cells. At first, all its elements were alike 
in structure and function ; later on, coincidently with its acquiring the 
capacity for moving in a definite direction, a change would take place. 
The form first becomes elongated, and it is interesting to observe that 
the free-swimming blastulse of both Echinocyamus and Eudendrium have 
this form. As the cells at the posterior end were least favourably situ- 
ated with regard to promoting the locomotion of the colony, and best 
situated for seizing food-particles, they would become specially digestive. 
Any increase in their number would only take place coincidently with 
invagination, if the form of the colony were to be preserved, and at the 
same time the digestive cells were to remain in contact with the sur- 
rounding medium. Thus was the archenteron formed. The cells at 
the anterior end, on the contrary, were in the best position for receiving 
stimuli from the outer world, and here we should expect the first sense- 
* The Society are not intended to be denoted by the editorial “ we,” and they do 
not hold themselves responsible for the views of the authors of the papers noted, 
nor for any claim to novelty or otherwise made by them. The object of this part of 
the Journal is to present a summary of the papers as actually published , and to 
describe and illustrate Instruments, Apparatus, &c., which are either new or have 
not been previously described in this country. 
f This section includes not only papers relating to Embryology properly so called, 
but also those dealing with Evolution, Development and Reproduction, and allied 
subjects. % Quart. Journ. Micr. Soc., xxxvii. (1895) pp. 325-42. 
§ See this Journal, 1894, p. 433. 
