June, 1920] GENETICS 'A0 ( .) 



strain C affFF, flat, and, with respect to this character, immutable. 



strain E «/9jF. 'hit, mutable. 



mut. formosa ot'Pfl, revolute-leaved. 



strain E X formosa a/3/7", flat, mutable. 



formosa X strain E «'/9/7". revolute, breeding true with respect to this character. 



strain C X formosa, Fj ctfiFf. Bat, segregating with respect to mutability. 



1 afiFF, flat, immutable, breeding true, 



strain C X formosa, F 2 <2 a(3Ff, flat, continuing the segregation of the Fi. 



1 aSff, flat, mutable, otherwise breeding true. 



formosa X strain C Fi a'PFf, flat, segregating with respect to revoluteness. 



[1 a'fiFF, flat, non-segregating. 



formosa X strain C F 2 -{2 a'pFf flat, continuing the segregation of the Fi. 



(l a'pff, revolute, breeding true. 



— Frieda Cobb. 



2101. Cockerell, T. D. A. Hybrid sunflowers. Nature [London] 102: 25-26. 1918. — 

 Results of hybridization in Helianthus: (1) varieties of annuus (including lenticularis) 

 crossed together give fertile hybrids; (2) interspecific hybrids between annual species; viz., 

 annuus crossed with argophyllus, petiolaris, and cucumerifolius, are nearly completely sterile; 

 (3) interspecific hybrids between annual and perennial species resemble one parent. Hybrid 

 previously reported between pujnilis and annuus is hybrid of subrhomboideus and annuus. 

 Brief discussion of interpretations of interspecific hybrid behavior. — R. E. Clausen. 



2102. Cole, Leon J., and Frank J. Kelly. Studies on inheritance in pigeons. III. 

 Description and linkage relations of two sex-linked characters. Genetics 4: 183-203. Mar., 

 1919. — Two sex-linked characters of domestic pigeon have been studied, namely intensity of 

 pigmentation (factor 7), and an alteration in the appearance of black pigment (factor A). 

 The A factor has variable effect on color of bird, differences depending, presumably, upon com- 

 binations of individual factors. There are apparently two main categories, dominant red 

 and gray. The dominant red presents an interesting contrast with the recessive red described 

 in previous publications. In the case of /, while the results were in accord with expectation 

 as to the association of character with sex, there was a considerable disturbance of the sex 

 ratio, the males being much in excess of expectation. This seems to be due largely to excess 

 of males in particular families, and may be the result of a recessive sex-linked lethal factor. 

 In the matings involving the A factor there was a deficiency rather than an excess of males. 

 No explanation is apparent. The two sex-linked factors I and A show slight but appreciable 

 mutual linkage. Crossing over in the male occurs in roughly 40 per cent of the cases; there 

 is no crossing over in the female.— Philip Hadley. 



2103. Collins, E. J. Sex segregation in the Bryophyta. Jour. Genetics 8: 139-146. PI. 6, 

 5 fig. June, 1919. — Author sowed 3 cultures of Funaria hygrometrica (monoecious): (1) from 

 antheridia taken from single male "flower"; (2) from perigonial leaves of male flower; (3) 

 from spores shed from one ripened capsule. Gametophytes from (3) were bisexual; those 

 produced vegetatively from (1) and (2) showed antheridia only. Suggests possible origin 

 of dioecism through somatic segregation in, and vegetative multiplication from, gametophyte 

 tissue. Discusses related work of the Marchals, Douin, Allen. — Merle C. Coulter. 



2104. Collins, J. L. Chimeras in corn hybrids. Jour. Heredity 10: 2-10. 7 fig. Jan., 1919. 

 — An article dealing with the occurrence of chimeras in certain plants and their possible ex- 

 planation. Grains of hybrid corn are reported in which xenia occurs only in a portion of the 

 aleurone layer, others having sweet patches in the starchy endosperm. The theory of inde- 

 pendent development of the second pollen tube nucleus and the endosperm nucleus is assumed 

 by Correns and Webber. In the present case it cannot hold because the purple half of the 

 seed should have had sweet endosperm, since the factor for purple aleurone and the factor 

 for sweet endosperm were carried in the same nucleus. East and Hayes suggest Mendelian 



