SUMMARY OF CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally invertebrata and cryptogamia), 
MICROSCOPY, Etc. 
Including Original Communications from Fellows and Others .* * * § 
ZOOLOGY. 
VERTEBRATA. 
a. Embryology.-}- 
Evolution and Epigenesis.J — Herr P. Samassa points out that F. v. 
Wagner, in his criticism of Hertwig’s views as to development, uses the 
words “ evolution ” and “ epigenesis ” as if they were meant to express 
that the conditions of development were from within and from without 
respectively. This is quite a mistake. The original usage of the two 
terms had no particular reference to the importance or unimportance of 
environmental conditions, nor has the modern usage. 
Experimental Biology.§ — The editor of the ‘ American Naturalist ’ 
has brought together in a convenient form notices of recent memoirs on 
experimental embryology published in Roux’s ‘ Archiv fur Entwickel- 
ungsmechanik.’ Mr. T. H. Morgan presents evidence to show that two 
blastulue of Sphser echinus may fuse together and form one embryo. 
Notwithstanding complete fusion, the future development of such 
blastulae gives evidence of their dual origin. Another paper by the 
same worker records a variation in the cleavage of the eggs of the same 
sea urchin, when shaken ; while most eggs divide into 2, 4, 8, and 16 
cells, some were found to divide at once into three. Eggs that have not 
been shaken sometimes divide at once into four cells. 
A third paper gives a detailed account of the partial larvae obtained 
when the eggs of the same urchin are shaken into fragments. Mr. Morgan, 
with Dr. Driesch, has investigated the remarkable half-larvae obtained 
* 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. 
t This section includes not only papers relating to Embryology properly so called, 
but also those dealing with Evolution, Development and Reproduction, and allied 
subjects. + Biol. Centralbl., xvi. (1896) pp. 368-71. 
§ Amer. Nat., xxx. (1896) pp. 76-82. 
