Descendenz und Hybriden. {(,() 



fungiert als Klebemittel. Das Sekret ist ein ätherisches öl und stellt 

 zwischen den Haaren benachbarter Blätter eine Verbindung her. Die 

 Haare zeigen ein intensives Wachstumsvermögen, schlingen sich leb- 

 haft durcheinander und bilden auf diese Weise einen dichten Haarfilz 

 über der Blattrosette. Beim Auseinanderweichen werden die Haare 

 starken Spannungen ausgesetzt und sie zeigen in Anpassung an 

 diese Verhältnisse eine zugfeste Konstruktion, die vor allem in einer 

 Tordierung der Zellreihen zum Ausdruck kommt. Nach Abschluss 

 der Sekretion verstärken sich die Membranen insbesondere im 

 basalen Teil. Die Zellulose der Verdickungschichten bildet das 

 Material zur starken Verlängerung des Haares, die zum Teil auf 

 Wachstumsvorgänge, zum Teil auf mechanischen Zug zurückzu- 

 führen ist. A. Jencic (Wien). 



DONCASTER, L., On the Inheritance of Coat-Colour in Rats. 

 (Proc. Camb. Phil. Soc. Vol. Xlll. [1905.] p. 215—228.) 



The colours dealt with are brown (wild colour), black, and 

 albino. Black and brown show each three types of pattern, described 

 by Crampe (Landwirt. Jahrb. VI. p. 384. 1877), and distinguished 

 as follows: Types 1 and 7 are füll coloured; 2 and 6 have white 

 on the ventral surface; 5 and 3 are piebald; the pigmentation being 

 brown in 1, 2 and 3 and black in 7, 6 and 5. Type 4 is the albino. 



The experiments deal chiefly with a) the power of albinos to 

 transmit colour or pattern when mated with coloured individuals, 

 and b) with the nature and relations of CJrampe's types 7, 6 and 5. 



It was found that some albinos carry the determinant for brown, 

 others for black, and others again for both brown and black. In the 

 case of pattern the phenomena were similar. Black is recessive to 

 brown and the pied character to ^self". 



As regards Crampe 's types, it was found necessary to sub- 

 divide one of them 6) into two Subtypes, one of which 6 b) appears 

 to be a heterozygote form produced by crossing either type 7 or 

 type 6 a with type 5. 



It further appears that type 7 is only an extreme form of type 

 6 a and cannot be separated from it as a distinct .variety. In other 

 words the divison between Crampe 's types 7 and 6 is shown by 

 further study of the germinal bebaviour to be only apparent; the 

 real constitutional distinction is between type 7 plus certain indi- 

 viduals of the appearance of „type 6" on the one band, and the 

 remainder of „type 6" on the other. R. H. Lock. 



Jeffrey, E. C, Morphology and Phylogeny. (Science. N. S. 

 XXIII. 1906. p. 291—297.) 



The Presidential Address presented to the Society for Plant 

 Morphology and Physiology in December 1905, deals with the 

 relations of fossil plants to the newer conceptions of Morphology, 

 and their important röle in determining questions of Phylogeny. 



D. P. Penhallow. 



Lock, R. H., Studies in plant Breeding in the Tropics. 

 IL Experiments with Peas. (Annais of the Royal Botanic 

 Gardens, Peradeniya. Vol. IL Oct. 1905. p. 357—414.) 



The author's summary is as follows : 



A somewhat complete summary of the more important of the 

 facts dealt with in the present notice has already been given in a 



