FIELD CROPS. 629 



appropriate nourishment, though the pollen apparently utilizes its own re- 

 serve material to some extent for its growth. 



Cross-fertilization and self-fertilization and the results in heredity, H. 

 Heukels (Rec. Trav. Bot. N6erland., 12 {1915), No. 3, pp. 278-339).— The 

 mode of treatment here emploj'ed is very largely that of genetics from a mathe- 

 matical standpoint and method, giving a discussion of results and conclusions 

 reported mainly by other writers. 



The question of mitochondria as bearers of heredity, H. Nachtsheim 

 (Naturw. WcJmschr., 29 (1914), No. 37, pp. 580^83) .—This is a discussion of 

 recent contributions and views regarding the part played by mitochondria in 

 heredity. 



The mutation factor in evolution with particular reference to CEnothera, 

 R. R. Gates (London: Macmillan tG Co., Ltd., 1915, pp. XIV +353, pis. 9, figs. 

 106). — This is a monographic treatment of the facts which bear upon mutation, 

 attention having been confined chiefly to Oenothera. The author states that 

 the book, in addition to summarizing present knowledge of the subject, contains 

 a large amount of hitherto unpublished material from his own studies and ex- 

 periments. 



Phases of evolution other than mutation are briefly discussed in the first 

 chapter. Subsequent chapters deal with the characters and distribution of the 

 CEnotheras, their cultural history, the mutation phenomena in CE. lamarckiana 

 and in other Oenotheras, the cytological basis of the mutation phenomena, 

 hybridization, and hereditary behavior, the relation between hybridization and 

 mutation, a general view regarding mutation and the lines along which a theory 

 of mutations should probably develop, and, finally, the evolutionary significance 

 of mutations, considering the mutation concept as related to heredity and 

 ontogeny, and mutation in relation to other evolutionary factors. 



An extensive bibliography is given. 



The genotypic composition of some varieties of the same species and their 

 genetical composition. Tine Tammes (Rec. Trav. Bot. Neerland., 12 (1915), 

 No. 3, pp. 217-277). — The author has studied the results of crossing among six 

 varieties of Linum nsitatissimuin. 



It is stated that flower color among these varieties was conditioned by two 

 or three factors. In close relation with flower color stand a number of other 

 characters which are named. The nature and results of color factor combina- 

 tions are detailed. 



Species crossing was entirely successful only between L. usitatissimum and 

 L. angustifoUum. Attempts at crossing these species with L. perenne, L. 

 austriacum, L. narbonense, L. grandiflorum, and L, flavmn gave no germinable 

 seed. 



Notes on the dissemination of Virginia creeper seeds by English spar- 

 rows, B. T. Hartoy (Plant World, 18 (1915), No. 8, pp. 2i7-2i9).— Observations 

 here noted regarding the retention of germinability of seeds of Virginia creeper 

 after distribution by sparrows suggest a degree of importance of this bird in 

 the dissemination of these seeds in central Colorado. 



FIELD CROPS. 



Report of the agronomist, T. S. Parsons (Wyoming Sta. Rpt. 1915, pp. 

 84-93). — A review of the work for the year 1914 is given and some of the more 

 important results are briefly noted. 



As compared with seed from other localities home-grown seed of 8 varieties 

 of oats gave an average increase in yield for two years of 12.98 bu., 9 varieties 

 of wheat 5.4 bu., and 10 varieties of barley 14.82 bu. per acre. In a test of 9 



