proceedings: botanical society 85 



selection in the conjugate generation are not good, on account of the 

 general uniformity of the plants. Selections have been carried in some 

 cases as far as 12 generations without securing evidences of stable com- 

 binations of desirable characters. Hybrids between Sea Island and 

 Upland varieties were not so good as the better class of long-staple 

 Upland varieties, when work with the hybrids was discontinued. 



Mr. H. V. Harlan discussed the behavior of barley hybrids. He 

 first called attention to the strikingly different characteristics of the 

 barley group and the sharply contrasting characters such as naked . 

 and hulled grain, black, purple, blue, or white colors, two and six-rowed, 

 awned and hooded heads, smooth and toothed awns, etc. Individuals 

 of the Fi generation in barley either may be intermediate in character 

 or may resemble one of the parents, and are quite uniform. In most 

 of these crosses the characters are inherited in a 3 : 1 ratio. The sub- 

 stitution of hoods in the place of the awn, which has a very decided 

 effect upon the physiology of the plant, is dominant to the presence of 

 awns. The smoothness or roughness of the awns behaves as a Men- 

 delian character. There is also a correlation between the smoothness 

 of the awn and the hairiness of the stigma. Crossing between the two- 

 rowed and six-rowed barley often results in an intermediate variety. 

 Such characters as the following: hulled and naked, black and white, 

 hooded and awned, are inherited in the 1 : 3 ratio. Fertility does not 

 necessarily follow the 1:3 ratio. 



Dr. C. E. Leighty discussed hybridization in wheat varieties and 

 species. Nine groups are available for hybridization : Triticum morio- 

 coccum, Triticum polonicum, wild wheat of Palestine, and six sub- 

 species of Triticum sativum. All of these species and subspecies hy- 

 bridize and fertile hybrids have been obtained, rarely, however, between 

 Triticum monococcum and any other group. Wheat and rye hybrids 

 have been secured always by using wheat as the female parent. 

 Aegilops ovata and triticoides have also been used in hybridization with 

 wheat. The first generation shows increased vigor, so far as noted, and 

 great uniformity. Most of the characters, however, are intermediate. 

 When wild wheat is used in hybridization the spikelets of the hybrid 

 fall apart as does the wild wheat. In the second generation segrega- 

 tion of most characters occurs in a 3 : 1 or 1 : 2 : 1 ratio, but in some cases 

 the ratio may be 15 : 1 or otherwise, as when a club wheat and wheat 

 with tapering head are crossed. In most cases the behavior can be 

 explained on the basis of Mendel's law. Wheat hybrids are often fixed 

 and many of the good commercial strains have originated in this way. 

 No bud variations or mutations have been noted. 



Mr. J. B. Norton discussed the crosses which he and Mr. A. D. 

 Shamel had made between wheat and rye. Wheat is always used as 

 the mother parent, as rye refuses to set seed with foreign pollen. The 

 first generation plants show great vigor, and though they resemble the 

 mother at first, at blooming time the resemblance to rye increases until 

 they would normally be mistaken for that plant. The hybrids are 

 nearly sterile, as out of thousands of first generation flowers only three 



