28 Tanake. 



a) for gametic repulsion: 



In these statements there are involved two important i)rolilems, 

 which I will briefly review below. 



1) Fluctuation of reduplication systems among the fra- 

 ternal individuals. The gametic series in hybrid males of the same 

 fraternity do not necessarily follow the same system of reduplication, 

 but in some of them 3:1:1:3 (in coupling) or I : 3 : 3 : 1 (in repulsion) 

 is the case, while in others 2:1:1:2 (in coupling) or 1:2:2:1 ratio 

 (in repulsion) fits best. Similar variation in the reduplication system 

 among individuals of the same fraternity was observed by some previous 

 authors, such as Gregory in Primula^), Punnett in the sweet pea^), &c. 

 The actual cause of such a variation is as yet obscure. 



2) Dimorphism of gametic series in male and female hetero- 

 zygotes. This phenomenon is most common in inheritance in which the 

 characters are sex -limited. Besides the sex -factor the similar cases 

 are, however, as yet rare, among wliich those by DE Vries in Oenothera^), 

 by Gregory in Primida*) and by Miss Saunders in Petunia^) and 

 Matthiola^) are to be mentioned. 



') Experiments with Primula sinensis. .Toiiin. Gen. Vol. 1, No. 2, 1911, 

 pp. 7.3—132, especially pp. 127—129. 



*) Reduplication Series in Sweet Peas. Jouin. Gen. Vol. .'3, No. 2, 191.3, 

 pp. 77—10:3, especially p. 86, Tables II and IX. 



') Über doppeltreziproke Bastarde von Oenothera biennis L. und O. murieata L. 

 Biol. Centralbl. XXXI, 1911, pp. 97—104. Gruppenweise Artbildung, 191.3, 

 pp. .30. 



') 1. r. p. 128. 



') Studies in the luheritance of Doublcncss in Flowers. I. Petunia. Jouru. 

 Gen. Vol. 1, No. 1, 1910, p. «2. 



•) Stocks. Doubling. Rep. Evol. Committee R. S., IV, 1908, pp. ■3f)— 40. 

 Further Experiments on the Inheritance of "Doubleness" and other Characters in Stocks. 

 Journ. Gen. Vol. 1, No. 4, 1911, pp. 317-.3f)0. 



