Appendixes 3 1 1 



Publication No. 143, 1911), who has investigated the 

 inheritance of abnormal venation on a very large scale, 

 chiefly with negative results which suggest that these 

 features are largely fluctuational. 



MOLLUSCA. 



Lang, Zts. indukt. Abstain., 1911, v. p. 97, has continued 

 and extended his researches on the genetics of H. nemo- 

 ralis and hortensis, and has found that in some cases, as 

 previously recorded, when these two species are crossed, 

 genuine hybrids are produced ; but in other instances the 

 results of the cross are purely maternal. This evidence 

 naturally suggests a comparison with the observations made 

 by those who have experimented with Echinoderm hybrids. 

 The literature of this latter subject is too extensive for 

 consideration on this occasion, and as no one has yet 

 succeeded in rearing the products to maturity the genetics 

 of the various species are still unknown. 



Appendix to Chapter IV. 



The analyses made by Nilsson-Ehle of the genetic 

 properties of Cereals have led him to the conclusion that 

 several factors all possessing the same property may co- 

 exist in one individual. For example, he gives evidence 

 that a certain wheat has in it three distinct factors having 

 the power of producing the red colour. Obviously such 

 possibilities must be remembered in future analyses, and 

 to them may perhaps be due various numerical aberrations 

 hitherto unelucidated. See especially, H. Nilsson-Ehle, 

 Kreuzungsuntersuchungen an Hafer und Weizen, Lund, 

 1909, p. 69. 



Some new types of ratio, brought about by the inter- 

 action of various factors leading to the masking of some of 

 the terms in the series, are discussed and illustrated by 

 Shull, G. H., Amer. Nat., 1908, p. 433. 



Appendix to Chapter VII. 



As stated above (p. 309) the analysis of the colours of 

 Horses has now been carried somewhat beyond the point 

 reached in this discussion. 



