82 Varietäten, Descendenz, Hybriden. 



has obtained of the occurrence of the two kinds of plastids in one 

 cell in meristematic tissue as definitely pointing to the localisation 

 of the abnormity in the chloroplasts themselves, rather than in the 

 cytoplasm. Such an hypothesis accounts for the maternal inheritance 

 of the character with which we are dealing, without raising the 

 question of the relative functions of nucleus and cytoplasm in the 

 case of the characters inherited in the usual way. The hypothesis 

 carries with it the assumption that the plastids of the Zygote are 

 derived solely from those present in the unfertilized egg cell. 

 Thus, variegated plants are invariably the ofifspring of variegated 

 mothers and give rise to green, variegated and yellow offspring, 



The green yellow offspring may be supposed to arise from egg 

 cells formed from pure green or pure yellow patches of tissue 

 occuring in the variegated mother plant. The variegated offspring 

 will have their origin from egg cells containing a mixture of the 

 two kinds of plastids, such as have been found in the cells of 

 young leaves of variegated plants. W. Neilson Jones. 



Jungelson, A„ Intoxication chimique et mutation du 

 Mais. (C. R. Ac. Sc. Paris. CLX. p. 481—483. 1915.) 



L'auteur a pu obtenir de Mais abnormaux, en partant de se- 

 mences plus ou moins intactes, et maintenues en contact, pendant 

 1 heure ä 24 heures, avec une Solution aqueuse ä 1 pour 100 oü 2 

 pour 100 de sulfate de cuivre electrolytique. II a recolte 150 epis, 

 dont 37 presentaient une deviation accentuee du type specifique. 

 Les grains, garnissant ces epis, ont ete influences par l'intoxication 

 de la semence-souche, et presentent certaines fluctuations interes- 

 santes portant sur leur conformation, leur structure anatomique, et 

 meme leur composition chimique. II est donc possible de mettre la 

 plante dans une p6riode d'affolement, de mutation creatrice de nou- 

 velles formes, non seulement par des processus m^caniques (Bla- 

 ringhem), mais aussi par des moyens d'ordre chimique. On peut 

 meme se demander si l'intoxication de la graine ou son evolution 

 dans un milieu chimique non accoutume n'est pas une cause directe 

 de l'apparition de types aberrants ou mutations. Jongmans. 



Miles, F. C, A genetic and cytological study of certain 



types of albinism in maize. (Journ. of Genetics. IV. p. 193 — 



214. 1915.) 



This paper commences with a summary of the published work 



on varying types of albinism (i.e. lack, or reduction in quantity, of 



Chlorophyll) in plants. 



The investigations of the author, which are then detailed, are 

 concerned with the inheritance and cytology (as affecting Chloro- 

 phyll distribution) of pale coloured or variegated races of maize. 



With the possible exception of the variety of Zea japonica 

 having striped leaves, the several degrees of albinism, found 

 behave as simple recessives when crossed with fully green plants. 



Breeding experiments indicate that at least two factors are 

 required for the development of normal green in the leaf: in the 

 absence of one of these factors the plant is pure white and soon 

 dies, while in the absence of the other the plant is at first yellowish- 

 white but is capable of developing into a greenish condition. 



