308 Descendenz und Hybriden. 



DONCASTER, L., On the Inheritance of Tortoiseshell 

 and related Colon rs in Cats. (Proc. Camb. Phil. Soc. 

 Vol. XIII. 1905. p. 35.) 



Inquiries from owners of pedigree cats yielded Information 

 which is interpreted as follows: 



Tortoiseshell is a heterozygous form produced by mating 

 orange with black, both of which colours can be bred true. 

 The answer to the question why are tortoiseshelis almost exclusi- 

 vely females appears to be that in the male orange is com- 

 pletely dominant over black, while in the female the dominance 

 is incomplete, and tortoiseshell results. 



Cream and blue appear to be dilute forms of orange and 

 black respectively, and have exactly similar relations to one 

 another. Creams can be obtained by pairing orange with blue, 

 in which case the dilution is transferred from the blue to the 

 orange yielding cream. 



When, as occasionally happens, male tortoiseshelis appear, 

 it must be supposed that in them the dominance of the orange 

 is incomplete. r. h. Lock. 



Hurst, C. C, MendeTs Discoveries in Heredity. (Trans. 

 Leicester Lit. and Phil. Soc. Vol. VIlI. Part II. June 1904. 

 p. 121.) 



A Short account of Mendel's experiments with peas, 

 which are illustrated and confirmed by similar experiments 

 undertaken by the author. The paper concludes with a survey 

 of the numerous examples both of plants and of animals in 

 which a similar behaviour of segregating characters has been 

 demonstrated. The author has himself observed the same pheno- 

 mena in a considerable number of different cases. 



R. H. Lock. 



Lloyd, F. E, The course of thepollentubein Hoiistonla : 

 a preliminary note. (Torreya. V. May 1905. p. 83 — 85.) 



The genus Houstonia is characterized by the lack of an 

 integument, hence the pollen tube cannot penetrate in the usual 

 way, but pursues a variable path through the placenta and 

 funicle. It is argued that the course of the pollen tube in 

 general has a physiological rather than phylogenetic signi- 

 ficance. M. A. Chrysler. 



Webber, H. J , and W. J. Swinole, New Citrus creations 

 of the Department of Agriculture. (Yearbook of the 

 United States Department of Agriculture. 1904. p. 221—240. 

 f. 12-13. pl. 10—22. 1905.) 



A report on work carried on since 1892. Two hybrids are 

 described between Citrus Aurantium and C. trlfollata, under 

 the name „citrange", neither very edible, but possessing distinct 

 table or culinary properties: both are more hardy than 



