626 EXPERIMENT STATION RECORD, 



perimeiits and observations on the origin of species in the vegetable kingdom. 

 A second volume will treat of the origin of varieties. Some additional material 

 has been included to bring the subject up to date. 



In the present work a discussion is given of the principles of the current 

 theorj' of selection, after which the author's investigations on the origin of 

 elementary si»ecies in the genus CEnothera are described at length. An ex- 

 tended discussion is given of the relative influence of nutrition and selection on 

 various characters, and it is shown that these two factors influence the plant 

 in the same direction, and when brought into conflict sometimes one and at 

 other times the other predominates. 



This translation will be found of great value to students and investigators 

 of plant and animal breeding to whom the author's earlier work is not available. 



The origin and relationship of new varieties of cereals, F., Kornicke (Arch. 

 Biontol., 2 {l<)0S-9). \o. ,.^ /*/*. J.'/fl-JJ? ).— The results of a botanical study of 

 the various species, varieties, and races of Triticum, Hordeum, and Avena are 

 given, with some notes on varieties of Panicum and maize. 



The wild type of the cultivated potato, P. Berthault (Conipt. Rend. Acad. 

 Sci. [Paris]. l.jO (1910), Xo. 1, pp. .',7-50) .—The results of a study of a large 

 number of varieties of cultivated potatoes, wild species in cultivation, and 

 herbarium material have convinced the author of the impracticability of deter- 

 mining from them the specific origin of our cultivated potato. He subjected 

 some of the wild species, especially Holanum commersonii, to the conditions 

 which are supposed to induce mutations, but thus far he has been unable to 

 recognize any specific modifications. 



The transmission of variations in the potato in asexual reproduction, 

 E. M. East (Connecticut State Sta. Rpt. 1909-10, pp. 119-160, pis. 5).— In a 

 previous paper (E. S. R., 20, p. 533) the author presented data which he thought 

 jiistified the conclusion that asexual fluctuations in case of the potato were not 

 inherited. Other investigations made it desirable to repeat his work, elimi- 

 nating as far as possible all experimental error. 



In 190() a number of foreign and domestic varieties of potatoes were gathered 

 together to observe the frequency with which differentiations occurred within a 

 variety reproduced by tubers. In 1907 other varieties were added until over 

 700 commercial varieties of potatoes were under investigation. Observations 

 were made upon this stock in 1906, 1907, 1908, and 1909. Among the unnamed 

 seedlings was one grown from seed of Early Rose, probably self-fertilized, that 

 had certain marked characteristics which made it valuable for study. This 

 was propagated and a considerable amount of material obtained for study. 



The fluctuation in dry matter and nitrogen content as due to high or low 

 nitrogen content in the seed tuber was investigated, and the author concludes 

 that neither the relative content of dry matter nor that of the nitrogen in the 

 potato can be changed by the selection of fluctuations and their subsequent 

 asexual reproduction. Studies were also made on the fluctuations in yielding 

 power, and it seems impracticable to recommend asexual selection to commercial 

 growers as a means of actual improvement of the crop. 



As a result of experiments as to the power of resistance to drought, disease, 

 and other external influences, while the author does not claim that the power 

 of resisting physiological or fungus diseases does not occur in asexual reproduc- 

 tion, he believes that the relative probability that the commercial grower will 

 obtain disease-resistant varieties by this means is negligible. In most cases 

 investigated, so-called resistance within a variety is believed to be due to non- 

 infection, and when there is a marked difference in vitality it is probably due to 

 differences in maturity, size of seed piece, varying soil fertility, or other causes. 



