SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally ixvertebrata and cryptogamia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Embryologry.t 



Action of Diluted Sea-water on Frogs' Ova and Larvae 4 — 

 Gr. Bohu and A. Drzewiua lind that small doses of diluted sea-water 

 have an excitatory influence on the hatching of frogs' ova and on the 

 growth of the embryos and larvae. Above and below the optimum, 

 monstrosities result. Solutions of JSTaCl, 5 parts in 1000, have a very 

 marked inhibitory influence on the hatching and on the growth of 

 the embryos, but much weaker doses seem to excite. Solutions of KCl, 

 unless in very weak doses, proved extremely toxic. These are, however, 

 but a few results of the extended and precise experiments. 



Action of Radium Emanation on Development of Frogs.§ — 



P. Wintrebert finds that a very weak dose of radium, similar to that in 

 the radio-active thermal water of Plombieres, has a favourable influence 

 on the development and metamorphosis of frogs, especially during the 

 growing period. 



Studies on Chromatin Maturation of Sex Cells. |1 — A. and K. E. 



Schreiner have studied the maturation of the male sex cells in Tomopteris 

 onisciformis. The first maturation division is heterotypic ; it separates 

 conjugated chromosomes from one another, and is, accordingly, a 

 reduction division. The second maturation division is homotypic ; in 

 it single chromosomes are longitudinally divided. It is, therefore, 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 'pub- 

 lished, and to describe and illustrate Instruments, Apparatus, etc., 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, Reproduction, and 

 allied subjects. 



X Bull. Internat. Acad. Sci. Cracovie, 1906, pp. 293-314. 



§ Comptes Rendus, cxliii. (1906) pp. 1259-62. 



II Arch, de Biol., xxii. (1905) pp. 1-69 (3 pis.). 



