SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(PRINCIPALLY INVERTEBRATA AND CR YPTOGAMIA) , 



MICEOSCOPY, Etc.* 



ZOOLOGY. 



VEBTEBRATA. 

 a. Embryology, f 



Development of the Heart in Pishes and Amphibians. £ — 

 Jaromir Wenig has studied the early development of the heart in 

 Scyllium, Pelobates, and Bufo, and comes to the conclusion that while the 

 mesoderm is chiefly responsible for the establishment of the heart, there 

 is a giving off of endoderm cells to share in forming the endothelium. 

 There seems to have been a transference of eudothelium-forming 

 function from endoderm to mesoderm, but the endoderm still assists. 



Yolk-granules of Amphibians. §— C. Saint-Hilaire discusses the 

 structure and chemical composition of tha yolk-granules, the changes 

 that they undergo in the cells of the larva, in degenerating ova, in the 

 phagocytes of various animals, in the intestine of Dendrocoelum lacteum, 

 and in Amoebae and Infusorians. The yolk-granules are quite definite 

 structural elements of definite chemical composition, specific in both 

 respects for different types. They may melt away as in the cells of the 

 larvae ; or become rounded and gradually dissolve, as in follicle cells ; 

 or become dissolved in vacuoles, as in amoeba; ; or break up into disks, 

 in rare cases ; or be gradually hollowed out, as in the cells of the intes- 

 tinal epithelium. There is a complex chemico-physical interaction 

 between the yolk-granules and the protoplasm of the cells in which they 

 find themselves. Substances pass from the protoplasm into the yolk- 

 granules and weaken them. Dissolved nutritive materials pass out from 

 the granules into the protoplasm. 



* 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 ia 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. 



% Morphol. Jahrb., xlviii. (1914) pp. 281-342 (2 pis. and 27 figs.). 



§ Zool. Jahrb. (Abth. Allg. Zool. I'hysiol.) xxxiv. (1914) pp. 107-232 (7 pis.). 



