SUMMAEY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VEBTEBRATA. 

 o. Embryologry.f 



Influence of Salt Solution on Early Development of Newt's 

 ~Egg4 — W. Tonkoff finds that very weak solutions (*5 p.c.) inhibit the 

 •development, without causing special abnormality in the cleavage. 

 ■Stronger solutions ( ; 6-*7 p.c) not only inhibit, but modify the de- 

 velopment. The difference in size between the cells of the two hemi- 

 spheres is accentuated ; the surface of the upper hemisphere is very 

 uneven; the gastrulation is irregular. In *8-* 9 p.c. solutions, there 

 is no gastrulation, cleavage is almost restricted to the upper hemisphere, 

 there is almost no blastula-cavity, the nuclei show signs of degeneration, 

 and so on. In 1 p.c. solution only a few cleavages occur. 



Artificial Fertilisation of the Ova of Cristiceps argentatus.§ — 

 Fr. Kopsch describes the comparatively easy way in which the ova of 

 this small Bleniid can be artificially fertilised by spermatozoa. This is 

 •of some scientific interest since the eggs of this fish are relatively large 

 and very transparent, — therefore admirably suited for morphological and 

 physiological study. 



Spermatozoa of Acanthias vulgaris.|| — G-. Retzius describes a spiral 

 band wound around the head of the spermatozoon and apparently run- 

 ning into the apex. It is very resistant and was disclosed by maceration. 

 ^Sometimes there were two parallel spirals. Retzius also finds inside the 

 "connecting-portion" of the spermatozoon a spirally coiled thread, 

 which is apposed to the distal centrosome-ring and is interpreted as a 

 proximal centrosome. 



* 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 tor 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 pvhlished, 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, Reproduction, and allied subjects. 



X Archiv. Mikr. Auat., lxii. (1903) pp. 129-37 (1 pi.). 



§ SB. Ges. Naturfreunde Berlin, 1902, pp. 33-6. 



\\ Biol. Untersuchungen, x. (1902) pp. 61-4 (1 pi). See Zool. Zentralbl., x. 

 <1903) P . 504. 



