ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 571 



origin. They issue from the nucleus by a sort of unequal amitosis or 

 budding. This phenomenon is connected (bj cases of less unequal 

 amitosis, where one nucleus degenerates) with the phenomenon of 

 nuclear dualism in certain glandular cells. It occurs when elaboration 

 is actiye. The pyrenoid bodies haye diyerse lots. They may give place 

 to pointed filaments ; they may behave as plastids ; they may divide at 

 the mitosis and persist without transformation on to the spermatid stage. 

 There are indications of what may be called special or accessory 

 chromosomes, but there is nothing to indicate that these are connected 

 with sex. The author cannot admit the individuality of the chromo- 

 somes, nor does he think that the manner of reducing the number of 

 chromosomes has the importance usually attached to it. The nucleo- 

 cytoplasmic relation is very important, but not the quantity of chromatin 

 in itself. It is an exaggerated view which gives the nucleus the exclu- 

 sive role as a vehicle of hereditary qualities. As an hypothesis it may 

 be suggested that the glandular tissue of the testis forms a hormone, 

 which acts as a spermatogenetic stimulant to the mother-sperm-cells. 

 This tissue has probably some action on the secondary sex-characters, 

 and serves as a sort of relay-station for the nutritive substances which 

 pass from the blood to the spermatozoa by the intermediation of the 

 cells of Sertoli. The memoir is very finely illustrated. 



Chondriosomes of Gonocytes of Teleosts.* — E. Aunap has investi- 

 gated the primitive germ-cells of Coregonus mardena^ which differ from 

 somatic cells in the possession of granular chondriosomes. He finds 

 that similar granular chondriosomes occur in the cleavage-cells. 



Embryonic Hydrocoele.j — L. von Betegh discusses the common 

 epidemic disease of alevins, which is known as yolk-sac dropsy or 

 " hydrocoele embryonalis." The yolk-sac becomes enlarged ; the 

 stricken alevins no longer rise to the surface : after a day or two the 

 yolk-sac bursts and the alevins die. The contents of the sac consist of 

 a serous fluid mass, which is at first quite transparent and later somewhat 

 turbid. It is full of a slender bacillus, which the author proposes to 

 name DijjJobacillus liquefaciejis pisciwn. The epidemic may be followed 

 by another disease, tympanites embryonalis, in which the whole gastric 

 region becomes distended, and the young fish bent. The larvag swim 

 back downwards, breathing with difficulty, and usually burst in six to 

 eight hours. 



Development of Caudal Hearts in Hag.| — AV. F. Allen describes 

 the lymphatics or veno-lymphatics of the adult, Polistotrema {Bdello- 

 stoma) stouti\ and the culmination of the system in two pulsating 

 hearts (as in Myxine and eels) which are enlargements of the caudal 

 vein. The caudal hearts are excavated out of mesenchyme through the 

 disintegration of the walls of large mesenchymal cavities, very much 

 as in the leech. The ventral veno-lymphatic trunk connected with the 

 heart also arises from coalesced mesenchymal cavities. A migration 



* Anat. Anzeig. , xliv. (1913) pp. 449-59 (5 figs.). 



t Sci. Invest. Fisheries Ireland, 1913, No. iii. pp. 1-4 (1 pL). 



i Quart. Journ. Micr. Sci., lix. (1913) pp. 309-60 (3 pis.). 



