196 



SCIENCE 



[N. S. Vol. XLV. No. 1156 



Vice-presidents, J. N. Rose, A. D. Hopkina, Hugh 

 M. Smith, Vernon Bailey. 



Secording Secretary, M. "W. Lyon, Jr. 



Corresponding Secretary, W. L. McAtee. 



Treasurer, Ned Dearborn. 



Members of Council, N. Hollister, J. "W. Gidley, 

 Wm. Palmer, Alex. Wetmore, E. A. Goldman. 



President Hay waa elected a vice-president of 

 the Washington Academy of Sciences. 



Ex-president Evermaim then gave an illustrated 

 lecture regarding the present condition of the mu- 

 seum of the California Academy of Science and 

 on its aims and aspirations. Dr. Evermann's lec- 

 ture was discussed by Messrs. E. W. Nelson and 

 Vernon Bailey. M. W. Lyon, Je., 



Recording Secretary 



THE BOTANICAL SOCIETY OF WASHINGTON 



The 116th regular meeting of the Botanical So- 

 ciety of Washington was held in the Assembly Hall 

 of the Cosmos Club at 8 p.m., December 5, 1916, 

 President T. H. Kearney presiding. The program 

 of the evening consisted of a symposium on the 

 behavior of hybrids in different groups of plants. 



Mr. G. N. Collins called attention to the increased 

 vigor of the first generation hybrids of Indian 

 corn which is particularly marked in strains which 

 have been widely separated geographically. Vari- 

 ability was found to be somewhat more character- 

 istic of the second than of the first generation. 

 Horny or sweet endosperm is perhaps the best ex- 

 ample of a simple Mendelian character pair thus 

 far encountered in maize. Horny and waxy endo- 

 sperm are completely alternative but the depar- 

 tures do not conform to the expected ratio. 



Mr. 0. E. Cook stated that when distinct types 

 of cotton are crossed there is usually evidence of 

 increased vigor and hardiness. As a rule, the first 

 generation is intermediate between the parents, 

 while the splitting is pronounced in the second and 

 later generations, but with no cases of complete 

 return to the ancestral types. A great deal of 

 correlation or coherence in characters is often 

 shown in the second and subsequent generations. 

 The increment of selection which has been de- 

 veloped in the parent stock previous to crossing is 

 totally lost in hybridization. 



Mr. H. V. Harlan called attention to the 

 sharply contrasting . characters in the barley group. 

 Such characters as the following: hulled and 

 naked, black and white, hooded and awned are 

 inherited in the 1-3 ratio. 



Among the wheats. Dr. C. E. Leighty stated that 

 nine groups are available for hybridization. The 



first generation shows increased vigor and greater 

 uniformity. Most of the characters are inter- 

 mediate. In most cases the behavior in subse- 

 quent generations can be explained on the basis 

 of Mendel's law. Wheat hybrids are often fiixed 

 and many of the good commercial strains have 

 originated in this way. 



The behavior of wheat and rye, oats and aspar- 

 agus hybrids was discussed by Mr. J. B. Norton. 

 A distinct coherence of characters is shown when 

 naked oats are crossed with the ordinary hulled 

 type. If Asparagus davuricvs, a Chinese species, 

 is crossed with Asparagus officinalis, the progeny 

 resembled in most cases the Chinese mother, espe- 

 cially in dropping their branches in the fall. 

 When these hybrids were crossed back with Aspar- 

 agus offi,cinalis, the second generation showed none 

 of the abcission phenomena exhibited by the 

 mother parent, although the expected ratio was 

 1-1. 



Resistance to wilt disease in hybrids of cotton, 

 okra, watermelon and covppea was discussed by Dr. 

 W. A. Orton. In the first generation of cotton hy- 

 brids, wilt resistance is dominant; in the second 

 generation a large percentage of non-resistant 

 plants are produced. Selected wilt-resistant plants 

 produced a third generation with marked increase 

 in resistance. In the case of cowpea wilt resistance 

 is limited to a distinct variety, ' ' the Iron. ' ' In 

 the ease of watermelon the citron or stock melon 

 was used in breeding for disease resistance. 



In hybrids of the Soy bean Mr. W. J. Morse 

 found the characters investigated to behave as 

 Mendelian characters and segregate according to 

 the Mendelian ratio. The only interrelation of 

 characters was noted in the case of the flower and 

 the hypocotyl, white flower being associated with 

 green hypocotyl and purple flower with purple 

 hypocotyl. Studies were also reported on cowpea 

 and alfalfa. 



The great differences in the behavior of citrus 

 from other groups mentioned was discussed by Mr. 

 Walter T. Swingle, who called attention especially 

 to the large amount of variability occurring in the 

 first generation hybrids. Many of these first-gen- 

 eration hybrids are of commercial value and may 

 be propagated without variation from seeds which 

 contain \isually only false embryos originating 

 from the nncellar tissues of the mother plant. In 

 a few cases there is a true second generation. 



Mr. L. C. Corbett and Mr. William Stuart took 

 part in an informal discussion which followed the 

 regular program. H. L. Shantz, 



Corresponding Secretary 



