320 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
SUMMARY OF CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally inyertebrata and cryptogamia), 
MICROSCOPY, Etc. 
Including Original Communications from Fellows and Others.* 
ZOOLOGY. 
A. VERTEBRATA: — Embryology, Histology, and General. 
a . Embryology. f 
Experimental Embryology.^ — Dr. W. Roux defends his position 
against the criticisms of Driesch and Hertwig. It will be remembered 
that according to Roux’s results, each of the first four blastomeres of the 
frog ovum forms, with a measure of independence, a quarter of the em- 
bryo, and that if one of the first blastomeres be punctured, the remaining 
half forms a half-embryo (right or left, anterior or posterior), and that 
the development generally proceeds like mosaic work. Each of the 
early blastomeres is specialised according to Roux, whereas according 
to Driesch and Hertwig they are all equivalent. 
The first part of his paper contains a detailed answer to some of 
Driesch’s criticisms, a counter-criticism, and an explanation of what is 
meant by self- differentiation as contrasted with dependent differentiation. 
Driesch shows that when pressure on the segmenting Echinoid ovum 
produces great disarrangement of cells, or that when some are entirely 
removed, a normal Pluteus larva is still formed, therefore, Driesch con- 
cludes, the blastomeres are for some time mutually equivalent. But 
he does not show that the normal result is attained in anything like 
the normal way. Roux would explain the normal result as due to the 
residual powers of regeneration and post-generation. 
The processes of regeneration and post-generation are then discussed. 
* 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., xiii. (1S93) pp. 612-25, 656-72. 
