394 Varietäten, Descendenz, Hybriden. 



zweiten Deutung läge der Fall vor, dass bei der weiss und rot- 

 blühenden Ausgangspflanze bereits in den Vegetationspunkten 

 (Embryonalgewebe) der Fi- Generation eine Aufspaltung stattfände. 

 Beide Fälle werden eingehend besprochen. Sierp 



Wheldale, M. and H. LI. Bassett. On a supposed synthesis 

 of Anthocyanin. (Journ. of Genetics. IV. p. 103—107. 1914.) 

 In this paper the authors uphold iheir view that the anthocya- 

 nin Pigments of plants are oxidation products of flavones and criti- 

 cise the contrary view put forward by A, E. Everest that antho- 

 cyanins are reduction products of flavones (Rov. Soc. Proc. 1914 

 Vol. 87B.) 



The principal points made by the authors are as follows: 



1. That Wheldale's hypothesis does not suggest that antho- 

 cyanms or flavones are at any time completely ^free from sugar, 

 as appears to be assumed by Everest. 



2. The fact that no glucoside of the flavones has been isolated 

 having more than one or two hydroxyl groups substituted by sugar 

 groups, does not preclude such bodies, of less stability, occurring 

 in the pl ant. 



3. Sufticient evidence has not been submitted by Everest that 

 the red Compounds obtained from flavones by reduction are com- 

 parable with the natural anthocyanins. The authors detail conside- 

 rations which lead them to regard this point as doubtful. 



W. Neilson Jones. 



Wilson, E. B., The bearing of cytological research on 

 heredity. (Proc. Roy. Soc. Lond. B. LXXXVIII. p. 333—352. 

 1914.) 



The author confines his attention to the chromosomes, since 

 investigation in this direction has yielded the most definite results 

 in connection with genetics. At the same time it is acknowledged 

 that the chromosomes are not the only determining factors of de- 

 velopment. 



The subject is dealt with in 4 sections. 



1. The 19th Century work. Individuality of chromosomes and 

 diploid nature of the nuclei of body cells postulated. Theoretical 

 suggestions of Roux, Weismann, de Vries &c. 



2. Opening of 20th Century and discovery of Mendel's work. 

 Demonstration that chromosomes derived from the male parent 

 unite with homologues from the female parent. Increasing evidence 

 that the chromosome content of the nucleus affects development 

 and the discovery that special types of individual are sometimes 

 associated with a special number of chrom.osomes. 



Proposal of hypotheses correlating chromosome behaviour with 

 „Mendels law". 



3. Discovery of sex chromosomes and the very strong support 

 afforded to the foregoing hypotheses by the results obtained from 

 investigations in this field. 



4. Gametic coupling — first clearly recognised in sex limited 

 heredity. Linkages of Mendelian factors having no relation with sex 

 subsequently brought to light and now known to be of rather wide 

 occurrence. 



The case of Drosophüa ampelophüa considered in detail. The 



