1914] CURRENT LITERATURE 93 



may always modify a homozygous character. The reviewer, taking a middle 

 ground, believes that the pure line work least subject to criticism, that on 

 self -fertilized material, does prove homozygotes to be sufficiently constant in 

 succeeding generations to make this constancy a basis for mathematical descrip- 

 tion, but he believes it to be unbiological to assert this constancy as absolute. 



As the basis of his assertion that there has been no proof of variation inde- 

 pendent of crossing, the author notices only the work of DeVries. Undoubt- 

 edly there is a great deal in favor of the idea that the Oenothera mutants are 

 the results of segregation from crosses, though the phenomena have not been 

 fitted into present Mendelian concepts. But that the very fine contributions 

 of Davis and Heribert-Nilsson on this subject have clinched the matter, 

 as Lotsy believes, would not be asserted, I venture to say, by the authors 

 themselves. It is pointed out very clearly that both the constructive work 

 of Gates in defense of the Oenothera mutations and his criticism of Heribert- 

 Nilsson are not so conclusive as that author so confidently asserts, but 

 this is only negative evidence. Moreover, the work of Morgan, Jennings, 

 Bateson, and others on the occurrence of mutations in controlled cultures is 

 complacently neglected. 



Lotsy's own extensive work on specific crosses in the genera Nicotiana, 

 Petunia, Pisum, and Antirrhinum, the constructive work of the paper, is 

 exceedingly interesting, and his detailed accounts, which are in press, will be 

 eagerly awaited. In brief, all the inter-specific crosses that he has undertaken 

 have shown true Mendelian segregation. The conclusion of DeVries, drawn 

 from the peculiar behavior of the Oenothera species, that inter-specific and 

 intra-specific crosses obey different laws of heredity, is shown, therefore, not 

 to be of general validity. — E. M. East. 



Cecidology. — Among the very important contributions to European 

 cecidology are Howard's papers on the collection in the Museum of Natural 

 History in Paris 9 and from Western Africa, 10 all of which are taxonomic in 

 character and well illustrated. The author uses the modern method of group- 

 ing the galls with reference to the host plants, which makes the data available 

 to those botanists who are interested in the study of malformations of plants 

 and in the relation of plants to other forms of life. 



Roll Howard 11 presents an exceptionally good paper on the anatomy of 

 the galls on the margins of leaves. He divides these malformations into four 

 groups; those caused (1) by hypertrophy and hyperplasia, (2) by hyperplasia, 



ard 



museum d'histoire naturalle de Paris: Galles de Burseracees. Marcellia 12:57-75. 

 1913; also Galles d'Afrique et Asie 12:102-117. 



10 , Les Galles de TAfrique occidentale fran^aise. VI. CScides du haut 



Senegal-Niger. Marcellia 12:76-101. 1913. 



11 Howard, Roll, Recherches anatomiques sur les Cecidies foliaires marginales. 

 Marcellia 12:124-144. 1913. 



