Morphologie etc. — Varietäten, Descendenz, Hybriden. 453 



(P. silvestris und P. puniilid). Den Schluss der Abhandlung bilden 

 phylogenetische Betrachtungen, dahin gehend, dass die Urstamm- 

 torm aller Kiefernarten eine vielnadelige Art wäre, nach Jeffrey: 

 PrepUius stateneusi^. Aus dieser ging wohl die fünfnadelige Stamm- 

 form der Kiefern hervor (fünfnadelige Kiefern der Kreideformation). 

 In der Entwicklung folgen dann die drei- und zweinadeligen Kie- 

 fern. F. mo)iophylln leitet sich von zweinadeligen Kiefern ab. 



Neger. 



Burtt-Davy, S., Observations on the Inheritance of Oha- 

 ra cters in Zea Mays. (Trans. Roy. Soc. South Africa. II. p. 

 261-272. 1912.) 



The author studied a cross between a Maize with starchy seeds 

 and a red pigment in the aleurone layer and a Maize with white 

 sugary grains: starch behaved as a simple dominant to sugar, and 

 pigment as a simple dominant to its absence, F9 exhibiting the 

 9:3:3:1 ratio. 



The number of rows on the cob is subject to fluctuation in the 

 same commercial strain: a normally 8-row type varies from 4 to 

 14 rows; and a normally 18-row t5^pe varies between 12 and 24 

 rows. The cross between an 8-row type and an 18-row type gives 

 an Fl with about 12 rows. 



White cob X red cob gives Fj^ with red cob, whichever way 

 the cross is made. R. H. Compton (Cambridge). 



Dobell, C, Some Recent Work on Mutation in Micro- 

 Organisms. I. Mutations in Try panosomes. (Journ. Gene- 

 tics. II. 3. p. 201—220. 3 textfigs. 1912.) IL Mutations in Bac- 

 teria. (Ibid. IL 4. p. 325-350. 1913.) 



A critical summary of some of the more important work pu- 

 blished during the last few years bearing on the production and 

 induction of mutations (permanent) and modifications (impermanent 

 changes) in certain Trypanosomes and Bacteria. The mutations are 

 classified as morphological (e. g. shape-changes) and physiological 

 (e. g. changes in resistance to drugs, in colour, and in enzyme 

 reactions). It is concluded that true mutations do occur in artificial 

 culture, both "spontaneously" and as the result of special Stimuli, 

 and that there is evidence of them occuring in nature also. The 

 mutations are regarded, following Frings heim, as "functional 

 adaptations" or "accommodations". R. H. Compton (Cambridge). 



Howard, A. and G. L. C, On the Inheritance ofSome 

 Characters in Wheat. I. (Mem. Dep. Agric. India. Bot. Ser. 

 V. 1. p. 1—46. 1912.) 



The authors have studied the inheritance of the following cha- 

 racters in Wheat: 



1) The presence of hairs ("felting") on the glumes. Various 

 types of hairiness were discovered, each due to a Single factor, and 

 more than one type may be present in the same plant. 



2) Red pigmentation in the grain, which appears to result from 

 the presence of one or more of three independent factors, as shown 

 by Nilsson-Ehle. The inheritance is necessarily complex and dif- 



