■618 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Colours of Bird's Eggs.* — Dr. 0. Laschenberg has published a 

 short abstract of his investigations into this subject ; the more im- 

 portant results are as follows : — As Krukenberg has stated, the ground 

 coloration originates in a different way from the spots and markings, 

 though both are derived from the blood and not from special pigment- 

 glands. The ground coloration is caused by a transudation through 

 the uterus which is richly supplied with blood-vessels ; the spots are 

 formed by particles of pigment which are found throughout the ovi- 

 duct and probably arise in the Graafian follicle ; the formation of 

 pigment is no doubt to be referred to a process similar to that which 

 causes the corpus luteum in the ovary of mammals. 



Development of Epicrium.t— Herren P. B. and C. F. Sarasin 

 have taken advantage of their visit to Ceylon to investigate the deve- 

 lopmental history of Epicrium glutinosum. The ovarian eggs are more 

 like those of reptiles than of amphibians, are oval in form, and about 

 9 mm. in their longest and 6 * 5 mm. in their shortest diameter ; there 

 was a considerable quantity of yolk, and a rounded whitish germinal 

 disk, in the centre of which is the darker germinal vesicle ; the arrange- 

 ment of the yolk was not unlike that which is seen in the bird ; in 

 the oviducts the ova become surrounded by a quantity of albumen, and 

 a spirally coiled cord appears at either pole. Epicrium, unlike its 

 American ally Ccecilia, lays eggs, and also hatches them. Embryos 

 about 4 cm. long move livelily in their shells ; on either side of and 

 behind the head arises a tuft of three blood-red external gills, which 

 constantly move about in the ovarian fluid. The three tufts vary in 

 length, the shortest being 2, the longest 9 mm. long ; the tail, which 

 is short but quite distinct, has a well-marked fin ; the eye appears to 

 be proportionately very large and distinct; dermal sensory organs 

 can be made out with the aid of a magnifying glass, and have the 

 appearance of white dots : the body is of a greyish-blue colour, clearer 

 below, and has a black stripe along the dorsal middle line; the two 

 beautiful yellow bands which are found in the adult are absent from 

 the embryo. The gills develope very early ; when they are lost, the 

 young pass into the nearest pool and begin to lead a free life. In 

 the water they grow to a length of about 16 cm., and lose their gill- 

 clefts and caudal fin; the structure of the skin changes, and they 

 become adapted to a terrestrial mode of life. 



The authors are of opinion that the Gymnophiona are to be asso- 

 ciated with or stand quite close to the Urodela ; as embryos they are 

 perennibranchiata, as larvae derotrematous, and in their adult terrestrial 

 condition they correspond to the Salamandrina. Embryology is sup- 

 ported in this view by histology, for the spermatozoa have been found 

 to have an undulating membrane, and by anatomy, for there is a fourth 

 arterial arch in the vascular system of the adult. 



Translocation forwards of the Rudiments of the Pelvic Fins in 

 the Embryos of Physoclist Fishes. —Mr. J. A. Eyder cites the 



* Zool. Anzeig., viii. (1885) pp. 243-5. 



+ Arbeit. ZooL-Zoot. Inst. Wiirzburg, vii. (1885) pn, 291-9. 



X Amer, Natural., xix. (1885) pp. 315-7. 



