SUMMARY OF CURRENT RESEARCHES. 521 



ou the yolk. On the third day the male began to fan them by con- 

 inually oscillating his pectoral and caudal fins. These actions kept, 

 the ova in a constant swirl, and were continued until the fry emerged 

 and took shelter in the weeds. There they were still guarded by the 

 male for about twenty-four hours. For about thirty-sis hours after 

 they emerged, the fry hung head downwards from the empty egg- 

 capsules by means of their tails, which were bent like the curve of a 

 fish-hook. 



Observations on Development of Toad.* — Laura Marchetti notes 

 that the adhesive suckers of the larva; of Bufo vulgaris appear at the 

 time of the medullary groove, as a V-shaped ventro-lateral groove. The 

 halves of the V form two suckers. The development of the suckers is 

 wholly due to the ectoderm or peri-ectoderm. The cells exhibit amoeboid 

 movement during the process of forming the groove. 



Pluripolar Mitoses in Regenerating Testes of Frog.f — Arnold 

 Lauche describes the occurrence of numerous pluripolar mitoses in the 

 testes of Rana fusca regenerating after partial castration shortly before 

 the breeding season. The peripheral spermatogonia show three indirect 

 nuclear divisions without any cell division. The case differs from pre- 

 viously described instances of the pluripolar mitoses in Amphibian testes, 

 inasmuch as the cells affected do not come to an end, but complete the 

 suppressed divisions, and from the lG-cell stage onwards follow a normal 

 course. The condition of the pluripolar mitoses is in part to be found 

 in the abnormal pressure-conditions resulting from the partial castration. 



Inheritance in Pigeons. J — L. J. Cole has made a study of the 

 inheritance of certain colours in tumbler pigeons and of some of their 

 modifications. The colours are red, black, yellow, dun, blue, silver, and 

 white, but only two kinds of pigment are concerned, red and black. 

 Red is potentially present in all birds, but shows only when not inhibited, 

 and when black is absent. For the full development of red and black 

 an intensity factor is necessary ; in its absence red appears yellow, and 

 black, dun. Blue results in the absence of a factor Which is assumed to 

 cause the pigment to spread throughout the barbules of the feather. 

 The dilute condition of blue is silver. White is due to an indefinite 

 number of factors which inhibit the production of pigment in the areas 

 which they influence. " Reversion " in domesticated pigeons is due 

 simply to a recurrence of the particular combination of factors present in 

 Colamba livia. The ratios of intense to dilute birds from heterozygotes 

 mated with other heterozygotes or with dilutes closely approximate to 

 Mendelian expectation, that is, 3 : 1 and 1 : 1 respectively. Matings of 

 the different colours give the results expected according to theory. A 

 considerable number of illustrative matings are presented. 



* Anab. Artzeig., xlv. (1914) pp. 321-47 (6 figs.), 

 t Arch. Mikr. Anat., lxxxii. (1913) 2te Abt., pp. 261-71 (1 pi.). 

 + Bull. Agric. Exper. Station, Rhode Island State College, No. 158 (1914) 

 pp. 313-39 (4 pis.). 



