May, L920] GENETICS 209 



occur if the two-pedicelled spikclcts were dropped simultaneously from a pair of yoked ali- 

 coles and accords with the hypothesis that the ear of maize is the result of the twisting of a 

 simple four-rowed branch. While the evidence of Zcu-Euridaena hybrids seems to require 

 the hypothesis suggested, there arc facts of other kinds which are more easily interpreted by 

 the theories of fasciation and reduction of branches and still others which do not seem to ac- 

 cord with any of the theories yet prop >s< d. The author concludes thai until the apparently 

 contradictory evidence can he reconciled it is best to keep the several possibilities in mind 

 and await additional evidence before ;,i t cm]) ting a complete interpretation. [See Bot. A.b 

 3, Entry 2421.]—/. //. Kempion. 



1473. Daiilguen, K. V. Ossian. Erblichkeitsversuche mit einer dekandrischen Cap- 

 sella bursa-pastoris (L.). [Genetical investigations with a decandrous Capsella bursa-pastoris 

 (L.).] Svensk Bot. Tidsskr. 13: 18-60. 2 fig. 1919. — Detailed history of the occurrence of 

 apetalous forms of Capsella and recognition of fact that these are not homogeneous. Two 

 tyoes of apetaly are recognized, (a) in which petals are replaced by stamens (decandrous), 

 and (b) in which petals simply fail (hexandrous). Genetical experiments were conducted 

 with the former type, in crosses with two of Almquist's elementary species, Capsella collina 

 and C. emarginata, and also with C. Heegeri and C. grandiflora. With C. grandiflora numer- 

 ous attempts failed to produce hybrids, except in one case in which a sterile plant was produced 

 which was probably such hybrid. In crosses with the other three forms, the Fi generation 

 was intermediate, but not always easily distinguishable in the F2 from the apetalous type. 

 When these intermediates are counted with the apetalous plants, the 3 : 1 F2 ratio is closely 

 approximated. Totals are 106 : 40, 44 : 16, 746 : 298, 1208 : 443; grand total, 2104 : 797. 

 The cross with C. Heegeri gave 394 with triangular capsules to 17 top-shaped, thus indicating 

 the presence of two genes for the triangular form, and the usual deficiency of the recessive 

 Heegeri type. Author cites further evidence that this deficiency is due to relative weakness 

 of the Heegeri type. [See Bot. Absts. 3, Entry 616.] — Geo. H. Shull. 



1474. Dehatjt, E. G. Developpement en sens inverse de la coloration verte, chez Lacerta 

 muralis tiliguerta et L. mur. quadrilineata. [Development of green coloration in reverse direc- 

 tion in Lacerta muralis tiliguerta and L. mur. quadrilineata.] Compt. Rend. Soc. Biol. 82: 

 514-515. May 17, 1919. — Fundamental dark color of young, probably primitive, gives way in 

 variable degree to green, which extends from behind forward in quadrilineata and in reverse 

 direction in tiliquerta. Green color has probably been developed independently in different 

 forms under influence of natural selection.— P. W. Whiting. 



1475. Dehaut, E. G. Interversion d'un caractere cranien dans certaines races du Sus 

 scrofa. [Interversion of a cranial character in certain races of Sus scrofa.] Compt. Rend. Soc. 

 Biol. France 82: 515-516. May 17, 1919. — Wild Sus scrofa and domestic continental swine 

 do not belong to different species, although angle made by plane of occiput and frontals is 

 acute in former and obtuse in latter. All gradations between these two forms are seen in the 

 Corsican and Sardinian swine. — J. A. Detlefsen. 



1476. de Vkies, Hugo, tiber erbliche Ursache eines friihzeitigen Todes. [On hereditary 

 causes of early death.] Die Naturwiss. 7: 217-222. 1919. — A list is given of plants commonly 

 producing seeds which develop into yellowish or etiolated seedlings (6 to 30 per cent) which 

 soon die. Author seeks the cause of the development of such seedlings in a mutation char- 

 acterized by the loss of the factor which has to do with the production of normal green color- 

 ing in the seedling. There may be a number of other factors the loss of which by mutation 

 also causes an early death of the seedling. These lethal factors follow in hybridization typical 

 Mendelian ratios as pointed out for Linaria vulgaris as well as for several species of Oenothera. 

 Two interesting mutants, Oenothera Lamarkiana mut. simplex and mut. velutina are noted 

 where the lethal factors (there seem to be two in these cases) which cause normally 50 per 

 cent sterile seed, are suddenly lost and all the seed produce viable seedlings. — Orton L. Clark. 



1477 de Vries, Hugo. Das Wandern der Pflanzen. [The migration of plants.] Die Nat- 

 urwiss. 7: 81-S9. 1919.— See Bot. Absts. 4, Entry 324. 



