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SUMMARY 
OP CURRENT RESEARCHES RELATING TO 
ZOOLOGY AND BOTANY 
( principally Invertebrata and Cnjptogamia ), 
MICROSCOPY, &c., 
INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* 
ZOOLOGY. 
A. VERTEBRATA Embryology, Histology, and General. 
a. Embryology. t 
Inheritance of Acquired Characters. J — Dr. J. F. van Bemmelen 
has written a detailed history of opinions and theories in regard to 
heredity, with special reference to the problem of the transmissihility of 
individually acquired characters. After a brief sketch of Weismann’s 
position, he reviews with great completeness the relevant literature. 
Beginning with Hippocrates and Aristotle, he passes to Buffon and de 
Maillet, Robinet, and Bonnet, and thence to Lamarck and the “ Trans- 
formists.” The opinions of modern naturalists are classified according 
to the predominance of anthropological, physiological, and pathological 
considerations. Scholarly as the record is, we find some serious omis- 
sions, as, for instance, of Brooks and Galton. 
Studies in Mammalian Embryology— The Placenta.§ — Prof. A. A. 
W. Hubrecht describes the placenta of Erinaceus europseus, and discusses 
the general history of placentation. 
I. Development of Yolk-sac and Allantois. — -The youngest blastocyst 
observed had the form of an oblong sac, and measured 1/10 mm. Its 
outer wall inclosed a few aggregated cells — the future hypoblast. The 
wall soon becomes more than single-layered, and exhibits an internal 
projection at the “ anti-mesometrical ” pole. Rapid growth thins out 
the wall of the blastocyst into a unicellular layer, with lacunar spaces 
containing maternal blood, and with numerous villiform processes from 
the columns intervening between the lacunae. From the thickened polar 
epiblastic knob, the germinal area is formed by the separation of an 
* 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. 
X ‘De Erfelijkheid van Verworven Eigenschappen,’ 8vo, ’SGravenhage, 1800, 
pp. xiii. and 279. § Quart. Journ. Micr. Sci., xxx. (1889) pp. 283-404 (13 pis.). 
