SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICEOSCOPY Etc.* 



ZOOLOGY. 



VE,RTEBRATA. 

 a. Embryology.t 



Teratogenic Influence of Saline and Saccharine Solutions. J — 

 E. Bataillon finds that this is in relation to the plasniolysis which is set 

 up in the developing egg, and may be measured in terms of molecular 

 weight and isotonic co-efficient. The optimum temperature for develop- 

 ment is not the same as that of the maximum resistance to plasmolysing 

 solutions. This maximum is about 15° C. for the egg of Rana tempo- 

 raria. Above and below this, blastoporic abnormalities are obtained 

 with weaker solutions than those requisite at 15° C. The inertia of 

 the vegetative pole is the initial trouble ; the prolapse of the vitellus by 

 a large blastopore follows as a consequence. But perhaps the most 

 important conclusion, telling against the theory of specific chemical 

 influence, is that at each temperature all isotonic solutions have the 

 same effect. 



Is there Parthenogenesis in Vertebrata ? § — Prof. K. Bonnet has 

 published a careful discussion of this interesting question, and reviews 

 161 documents bearing on it. He comes to the conclusion that we are 

 not as yet warranted in speaking of parthenogenetic processes in Verte- 

 brates. The phenomena which have been described as parthenogenetic 

 are partly degenerative and partly the results of imperfect or feeble 

 fertilisation. So-called parthenogenetic tumours are interpreted as the 

 results of the development of a blastomere which has got separated off, 

 or has divided with abnormal slowness. 



Division of Chromosomes. || — Dr. E. V. Wilcox discusses the ques- 

 tion whether there is really that sharp distinction between longitudinal 

 and transverse division of the chromosomes which Weismann supposes. 



* 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, 

 hut also those dealing with Evolution, Development, Reproduction, and allied subjects. 



X Comptes Rendus, cxxxii. (1901) pp. 852-4. 



§ Anatomische Ergebnisse (Merkel and Bonnet), ix. (for 1899) pp. 820-50. See 

 Zool. Centralbl., viii. (1901) pp. 341-2. || An at. Anzeig., xix. (1901) pp. 332-5. 



Aug. 21st, 1901 2 e 



