Park: Selection in Uroom Corn 



219 



being an important aid in many plant 

 breeding experiments where seasonal 

 influences obscure the efifect of genetic 

 factors. Of course, the idea is old, 

 and has been used many times, but the 

 method deserves wider recognition and 

 more general use. It is best adapted 

 to experiments with those plants that 

 produce an abundance of seed which 

 is viable over a period of years. With 

 several generations of a selection exper- 

 iment all growing side by side, progress 

 could be measured with much greater 

 accuracy than by comparing generations 

 of plants which were grown in different 

 seasons. 



Table I. The average values for certain 

 characters in typical head-roiv popula- 

 tions of broom corn, 1918. 



The Protection of the Germ Plasm 



Keimesfuersorge : Entstehung und 

 Verhuetung der Schwangerschafts- 

 stoerungen, by Dr. Alfred Greil, 

 Insbruck. Pp. 37. Price, 16 cents. 

 Leipsig, Verlag von Curt Kabitzsch, 

 1923. 



That the child's future is largely 

 influenced by the conditions surround- 

 ing the embyro, and particularly by 

 the presence of various bodily poisons 

 in the mother's blood, is Dr. Greil 's 

 thesis. This proi)Osition is expounded 

 in a detailed and sometimes startling 

 way ; but the treatment is dogmatic 

 (perhaps necessarily so because of the 

 brevity of the paper), and the reader 

 is given no idea of the evidence be- 

 hind many interesting statements. Dr. 

 Greil holds that the gametes deterior- 



ate rapidly after separation from their 

 place of origin, hence the importance 

 that zygosis should occur promptly. 

 Thereafter, the most important fea- 

 ture of his program seems to be a 

 not too nitrogenous diet for the 

 mother. A statement of the necessary 

 conditions for the maintenance of 

 health in the germ-plasm is given. It 

 is announced that an English edition 

 of this pamphlet is in preparation ; it 

 is much to be desired that the author 

 present some of the evidence under- 

 lying his views, since it is not gen- 

 erally familiar to geneticists, who will 

 have to be shown the facts before 

 admitting that the author's ideas are 

 anything more than "important if 

 true." — P.P. 



