O20 Referate. 



kehren in der gleichen Breite auf der linken (bzw. recliten) Hälfte des 

 nachfolgenden Blattes in umgekehrter Reihenfolge wieder." 



Dies beruht darauf, daß die Blätter in zwei diametral gegenüberstehenden 

 Reihen angeordnet sind, und mit ihrem Grunde den Stengel völlig umfassen. 

 Die reproduzierten Figuren, in denen schematisch 2 aufeinanderfolgende 

 Blätter in eine Ebene projiziert sind, erläutern diese Verhältnisse. 



Die Pflanze bildet also in vieler Beziehung ein Gegenstück zu Baurs 

 Pelargonien. Ihr Vegetationskegel ist aus zahlreichen, grünen und weißen 

 Sektoren verschiedener Breite zusammengesetzt. Acliselsprosse, die zufällig 

 völlig in einen grünen Sektor fallen, bleiben reingrün, solche die aus einem 

 weißen derivieren, rein weiß. Es wäre von Interesse zu erfahren, wie sich 

 ihre sexuelle Nachkommenschaft verhält. H. Buder. 



Spillman, W. J. Inheritance of "£/e " in Vigna. Am. Nat. 45: 513— 23. 1911. 



Spillman has studied various races of the cow pea (J'igna unguiculata) 

 with special reference to the manner in which certain seed coat color 

 factors are inherited. Races were investigated in which pigmentation of 

 the seed coat was complete, in which it was incomplete, and in which 

 pigment was wholly lacking. The data presented refer largely to the study 

 of the partially pigmented races in which the color is distributed around 

 the hilum in a peculiar pattern commonly known as ''Eye'. 



The investigation discloses four distinct types of ^'Eye\ to which the 

 names Small Eye, Large Eye, IVatsoii Eye and Holstein Eye have been 

 given. Small Eye varies considerably in the extent of its pigment pattern, 

 — from that of a pigment spot on each side of the hilum to an area 

 covering about two fifths of the ventral surface of the pea. Holstein Eye 

 is divided into two classes; one in which the pigment area has extended 

 over the micropylar end of the seed, the other in which the pigment covers 

 the whole seed with the exception of the dorsal portion of the chalazal 

 end. In both types small pigment spots are present in these non-pigmented 

 areas. In Large Eye, the pigment covers nearly the whole ventral surface 

 and has a characteristic notch at the micropylar end. The data thus far 

 collected indicate that this form of "jS)r" is always heterozygous for the 

 factorial difference between Holstein Eye and Small Eye. Three classes of 

 Small Eye have been distinguished and there is some evidence that they 

 are the DD, DR, RR of a Mendelian pair. The study of these three 

 classes is very complex and their investigation is being continued. The 

 fourth type, the Watson Eye, is genetically distinct from the Holstein Eye, 

 although similar to it in appearance. In this pattern the pigmented area 

 surrounds the hilum, and the micropylar end of the area has an indistinct 

 margin, stipuled with fine pigment granules. 



Sjnall Eye x Solid Color (complete pigmentation) gave in Fi dominance 

 of Solid Color. F.2 gave individuals of Solid Color, Watson Eye, Lfolstein Eye, 

 Large Eye and Small Eye in the proportion of 9:3:1:2:1 respectively. 

 In some of the families of the Fo generation, the Large Eye and .Small 

 Eye producing individuals were not separated. In such cases the ratio 

 approximated 9:3:3:1, in which the heterozygous portion of the third 

 class plus the fourth class constitute 3 instead of 2:1 as given in the 

 previous ratio. 



Holstein x Solid Color gave in Fj complete dominance of Soldid Color. 

 Out of 100 F, individuals, 75 produced Solid Color seeds and 25 Holstein 

 seeds, making the ratio an exact 3:1. 



