302 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



body in the growth stage, and during the formation of the spermatozoon 

 it becomes more and more conspicuous, till it assumes the appearance of 

 a small spherical body and comes to be situated in a depression at the 

 anterior part of the nucleus. It seems to have no connexion with the 

 centrosome. Mitochondrial granules are abundant during the growth 

 stage. Second pairing of chromosomes is not found, but as in the case 

 of the horse incomplete fusion of the chromosomes is seen to occur. In 

 such a case nine or ten chromosomes are occasionally to be counted. 

 The chromatoid corpuscle cannot be found, but during the reduction 

 division a small spherical body, staining faintly with iron-ha3matoxylin, 

 appears in rare cases in the cytoplasm. J. A. T. 



Development of Gobies.— C. G. Joh. Petersen {Report Danish 

 Biol. Stat, 1920, 26, 45-66, 3 pis.). Notes on the young stages of 

 five species of Golius and of Lebetus, Crystallorjolius^ and Aiihya, with 

 particular attention to the pigmentation at various stages. The eggs of 

 gobies are found in enormous numbers in Danish fjords ; the develop- 

 ment as a rule takes place in less than a year ; there is considerable 

 migration of the adults of several species. The chief aim of the paper 

 is to facilitate the identification of the young stages of different species 

 of Gobiid^. J. A. T. 



Development of Vascular System in Embryo Stickleback. — R. 

 Anthony lArch. Zool. Exper., 1918, 57, 1-45, 1 pi., 31 figs.). A study of 



Larva of Stickleback {Gasterosteus ^^/^mi^^r-ws), thirty-eight hours 

 after hatching. 



0., eye; C, heart; V.a., auditory vesicle; R.b., branchial rays; 

 G.h., oil globule; "r.i;.?^., median vitelline vein; B.v., vitelline 

 plexus; iS^.;?., pectoral fin; V.s.i., sub-intestinal vein ; I.p., pos- 

 terior intestine ; V.ii., urinary bladder ; V.c, caudal vein ; A., aorta ; 

 Ch., notochord. The arrows indicate the direction of the blood- 

 current. The pigmentation is not indicated. 



the beginnings of tiie circulation and of the vitelline circulation in par- 

 ticular in Gasterosifi2is f/i/mnur us, vf'ith comparison with other Teleosteans. 

 The primitive pathway of the blood returning to the heart from the 

 aorta is a simple large venous vessel, fed by caudal, anal, and sub-intes- 

 tinal veins, which runs to the left on the vitellus. There is a complete 

 circuit before there is a vascular vitelline network. The first vitelline 

 circulation in the stickleback is entirely venous. But when the vitelline 



