134 



"Comparison with the embryo of sedges also supports the view 

 that the scutellum and coleoptile together represent the cotyledon. 



" As a result of her anatomical study of the seedlings of mono- 

 cotyledons, Miss Sargeant came to the conclusion that the single 

 cotyledon was the result of fusion of two cotyledons. The specimen 

 exhibited shows a seedling of Zea main [in which the cotyledon 

 sheath (coleoptile) is bifurcated at the apex, and possesses two 

 vascular strands throughout its length. Numerous seedlings raised 

 at the same time as the specimen exhibited showed the same phe- 

 nomenon, though the degree of bifurcation varied. In all cases, 

 however, there were two vascular strands. 



" The case in question cannot therefore be regarded as a mere 

 monstrosity, and may well be in the nature of a reversion to the 

 ancestral condition." 



Mr. Eobert Adkin exhibited eight representative series of families 

 of Boarmia gemmaria reared through successive years from captured 

 females of the black form. He said that the present exhibit was in 

 continuation of one that he made five years ago (" Proc," 1910, p. 

 151). The race that he was then dealing with had become weakened 

 by interbreeding, and appeared to be on the point of dying out, and 

 as a matter of fact five moths only, all of the black form, were reared 

 in 1911, these, however, formed the one stock from which the series 

 now exhibited were descended, and would be referred to as X. The 

 other stock was obtained from a female of the black form taken wild 

 in 1910, and from the ova which she deposited a brood consisting 

 of 67% typical and 83% black imagines were reared in 1911, and 

 which will be referred to as Z. 



A. B. C. brood. Three typical males Z were paired with thre^ 

 black females X, and in 1912 produced a brood of black imagines of 

 which 39% were males and 61% females, the black characters in the 

 weakly stock X thus apparently for the time overcoming the typical 

 characters in the more robust stock Z. 



D brood. A black male Z was paired with a typical female Z, 

 and in 1912 produced a brood consisting of 44% typical (66% male 

 and 34% female) and 66% black (49% male and 51% female). 



E brood. A black male and female A. B.C. were paired, and in 

 1913 produced a brood of which 22% were typical (70% male and 

 80% female) and 78% black (75% male and 25% female), thus it will 

 be seen that although no typical characters had been intentionally 

 introduced they had reasserted themselves in the second generation. 



G brood. A black male A. B.C. was paired with a black female 

 D, and in 1913 produced 50% typical (42% male and 58% female) 



