SUMMARY OF CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally invertebrata and cryptogamia), 
MICROSCOPY, Etc.* 
ZOOLOGY. 
VERTEBEATA. 
a. Embryology* t 
Experiments on Heredity 4 — Prof. J. C. Ewart has collected his 
previous papers describing liis “ Penycuik experiments,” some of which 
have been already reported in this Journal, aud has prefaced them with 
a general essay, in part introductory and in part supplementary. The 
book is beautifully illustrated with photograms. The chief results may 
be summed up as follows. 
(1) By numerous experiments in hybridising, Prof. Ewart has placed 
the doctrine of reversion on a firmer basis than it has hitherto had. 
Thus a pure white fantail cock-pigeon, which in colour proved to be 
prepotent over a blue pouter, was mated with a cross previously made 
between an owl and an archangel, and the result was a couple of fantail- 
owl-archangel crosses, one resembling the Shetland rock-pigeon, and the 
other the blue rock of India. And again, a smooth-coated white rabbit, 
derived from an Angora and a smooth-coated white buck, was mated 
with a smooth-coated, almost white doe (grand-daughter of a Himalaya 
doe) ; and the result was that in the litter of three, one is the image of 
the mother, one is an Angora, like the paternal grandmother, and one is 
a Himalaya, like the maternal great-grandmother. 
(2) Some interesting facts are given in regard to the origin of “ pre- 
potency ” as a result of inbreeding, and the important suggestion is 
made that prepotency may be an important evolution-factor, accounting 
for the persistence of variations in their early stages. 
(3) The two aspects of inbreeding are very clearly illustrated : on 
* 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. f 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. 
X ‘ The Penycuik Experiments,’ by J. C. Ewart. London, 1899, 8vo, xciii. and 
177 pp., 46 figs. 
