Descendenz und Hybriden. 329 



Dans une troisieme partie, l'auteur fait un examen com- 

 paratif de l'origine, du developpement des organes reproducteurs, 

 et des phenomenes de la fecondation chez les Angiospermes 

 et les Gymnospermes. La comparaison des phenomenes morpho- 

 logiques de la fecondation observes chez les animaux et les 

 plantes constitue la quatrieme partie de l'ouvrage qiii se termine 

 par l'interpretation des phenomenes de la fecondation. 



Paul üuerin (Paris;. 



Bateson, W., Miss E. R. Saunders, R. C. Punnett, and C. C. Hurst, 



Report to the Evolution Committee of the Royal 

 Society. (II. 1905.) 



Miss Saunders contributes experim^nts with Datura, 

 Matthiola, Salvici hovminiim and Rannnciilns arvensis. 



In the case of Matthlola the results are presented under 

 the following heads: I. Significance of some apparently uncon- 

 formable cases. II. Further experiments with recessives. III. 

 Colour inheritance. IV. Frequency of occurrence of double 

 flowers. V. Experiments with Matthlola slnuata 



The principal experiments deal with the phenomenon of 

 reversion in surface character of the leaves and in the colour 

 of the flowers, which is found to occur on crossing various 

 strains; and with the further behaviour of the offspring of the 

 reversionary plants. For details reference must be made to the 

 original paper. 



The results obtained from the crosses with Salvla hormlnum 

 entirely support MendeTs conception of germ purity. Of the 

 three strains violet, pink, and white, the two latter are both 

 recessive to violet. On crossing violet with either white or pink 

 a simple Mendelian result was obtained. Crosses between pink 

 and white showed in one case dominance of pink, in others 

 reversion to violet. The latter plants on seif fertilisation yielded 

 the following: V 314, P 117, W. 148 



In the case of Rannnciilns arvensis, on crossing the type 

 (miirlcatiis) with var. Inernils, niiirlcatiis was found to be do- 

 minant. On crossing var. tiiherculatiis with var. Inermls the 

 resulting fruits showed a character intermediate between those 

 of tnh er eil latus and miirlcafus (partial reversion). 



Experiments on Plsiun sativum are reported by W. B ateso n 

 and Miss Killby. The general result is stated as follows : 



„The net result of our work tends to the conclusion that 

 Mendelian principles in regard to heredity in peas are capable 

 of an application more literal than at first seemed likely. Diffi- 

 culties based on the supposed variability of the seed characters 

 in the type have proved to be small, and it is doubtful whether 

 there are any genuine ,,exceptions" which cannot be traced to 

 interference of conditions or mistakes". 



A third class of cotyledon colour is added to yellow and 

 green, namely Piebald, tinged or yellowed, e. g. „Te- 

 lephone". In seeds of this class the originally green cotyledons 



