78 The Journal of Heredity 



culiarity of a ]jractically indeterminate tations belonj^nnt,^ to this second class as 

 growth. they bred true and could therefore be 

 DeVries recognized two tyj^es of distinguished from variations due to 

 mutation: (1), a germinal change in hybridization. These tobacco muta- 

 either the male or female reproductive tions seem to belong to the class in 

 cell before fertilization, in which case which a change has taken j^lace after 

 the mutating individvial was a first fertilization. DeVries also believed in 

 generation hybrid and did not breed periods of mutation. From this stand- 

 true; and (2), a mutation after the point the constantly recurring variation 

 union of the male and female reproduc- in the Connecticut Havana variety is of 

 tive cells. He chiefly emphasized mu- some interest. 



NEW PUBLICATIONS 



EINFUHRUNG IX DIE EXPERIMEXTELLE VEREBUXGSLEHRE, von Prof. Dr. 

 phil. et mcd. Erwin Baur. 2. ncubcarbeitcte Auflage mit 131 Texlfiguren und 10 farbigen 

 Tafeln. Verlag von Gcbrudcr Borntraeger, Berlin W. 3.S, 1014. Pp. 401, 14 ink., 50 pfg. 



Dr. Baur's Introduction to Genetics, which was published in 1911, has been 

 reissued after complete revision which brings it up to date. It covers much the 

 same ground as the text-books of Plate and Goldschmidt ; one must regret that no 

 English genetist has yet produced a text-book on similar lines. Although intended 

 primarily for students, Baur's work will be of interest to every genetist, because 

 of the extent to which he has drawn on his own researches for illustrative material. 

 The book, as its title promises, confines itself as nearly as possible to experimental 

 data, admitting only as much theoretical discussion as seems absolutely necessary ; 

 the c\i:ological section has also been reduced to a minimum. The illustrations are 

 particularly good. A bibliography of 30 pages will be welcomed by many. 



THE FUXDAMEXTALS OF PLAXT BREEDIXG, by John M. Couller. Pp. xiv-h346, 

 109 figures, price SI. 50. Xew York and Chicago, D. Appleton and Company, 1914. 



Dr. Coulter, head of the department of botany of the University of Chicago, 

 has written this book for "those who wish a simple statement of evolution and 

 heredity; who wish information concerning the revolution in plant breeding; or 

 who wish a general introduction to the fundamental principles imdcrlying agri- 

 culture. This should include citizens interested in the things that make for the 

 public welfare, farmers, students of agriculture, teachers in the ]jublic schools, 

 and botanists." People belonging to these classes will find it useful and satis- 

 factory; it tells the story of the application of genetics to horticulture and agri- 

 culture in a comprehensive, although necessarily general way, and does so under- 

 standablv. These qualities are certain to secure it a wide welcome. The typography 

 and illustrations, however, are not worthy of the book. 



Restrictions of Marriage 



There may be some who think the li^nglish would be happier if tlieir marriages 

 were arranged at Westminster, instead of, as hitherto, in Heaven. I am not of 

 that opinion, nor can I sujjijosc that the constructive pro]wsals even of the less- 

 advanced eugenists would be seriously supi^orted by any one who realized how 

 slender is our present knowledge of the details of the genetic processes in their 

 application to man. Before science can claim to have any jKisitive guidance to 

 offer, numbers of untouched jjroblems must be solved. As regards i)ractica] 

 interference there is nevertheless one perfectly clear line of action which we may 

 be agreed to take — the segregation of the hoi)elessly unfit. — William Bateson. 

 Biological Fact and the Structure of Society (1912). 



