SUMMARY OF CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally invertebrata and cryptogamia), 
MICBOSCOPY, Etc. 
Including Original Communications from Fellows and Others .* * * § 
ZOOLOGY. 
YERTEBRATA. 
a. Embryolog-y.f 
Experimental Embryology 4 — Prof. 0. Hertwig subjected fertilised 
ova of Bana esculenta to tbe influence of rapid rotation, and observed 
the remarkable “ Mecbanomorpboses ” induced by tbe centrifugal force. 
The apparatus described 145 rotations per minute ; some of tbe ova, 
those most under tbe influence of tbe centrifugal force, failed to develop 
at all ; others, only slightly influenced, developed normally ; a third set, 
24-32 cm. from the centre, developed almost meroblastically. This 
interesting result was apparently due to an artificial accentuation of the 
normal polar differentiation of the frog’s ovum. Left in the machine 
they did not develop beyond the blastoderm stage ; but if transferred 
within 24-48 hours to normal conditions, they developed into embryos, 
some of which showed the frequent spina bifida abnormality. 
Removal of Shell from Developing Ova.§— M. Ch. Fere has suc- 
ceeded in directly observing the development — which tends to be 
abnormal — of eggs from which the shell has been wholly or partly 
removed. He tried three methods : — (a) opening the upper side and 
replacing the shell by a watch-glass ; (b) opening the posterior end 
(Beguelin’s method) and re-covering it with part of a shell from another 
egg ; (c) placing the whole egg without its shell in a glass vessel. Two 
results are clear — that the embryo has more power of resistance to such 
disturbances than is usually supposed, and that the method is useful in 
experimental teratological work. 
* 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. X SB. K. Preuss. Akad. Wiss., 1897, pp. 14-18 (1 fig.). 
§ Journ. de l’Anat. Physiol, xxxiii. (1897) pp. 259-G6. 
