748 



SCIENCE. 



[N. S. Vol. XVllI. Xo. 407. 



nineteen individuals (and tolerably vigor- 

 ous larvae they were) alive in the lot which 

 had experienced two years of famine, al- 

 though every individual of the 149 hatched 

 was carefully preserved and royally fed 

 —a fact which goes to prove that the equip- 

 ment at birth of many of these larvffi was 

 inadequate. 



The fact that some larvte of starved an- 

 cestry have exhibited a superiority over 

 their fellows, in surviving and recovering 

 from hard conditions, is testimony for the 

 existence of individual variations which 

 can not be defined anatomically, and yet 

 which serve as 'handles' for natiiral selec- 

 tive agents. Such variations might be 

 called physiological variations, since it 

 seems that the surviving larvte must be 

 those which are in best trim physiologically. 

 These larvae are able to make the most of 

 the food offered to them. If competition 

 were allowed, they would probably be the 

 individuals which would cover the area 

 most rapidly, securing whatever food there 

 might be. But under our experimental 

 conditions there Avas no competition allowed 

 and yet certain precocious individuals made 

 more grams of flesh and more yards of silk, 

 than other larvce furnished with the same 

 amount of raw material under like condi- 

 tions; that this was due to the possession 

 by the former of certain congenital qual- 

 ities of adaptability "can scarcely be 

 doubted. 



6. As to the fertility of the variously 

 fed lots; in so far as number of eggs pro- 

 duced is a measure of fertility, our records 

 already demonstrate the fact that the 

 better nourished are the more fertile. 

 Furthermore, the economy in this matter 

 practised by the starvelings is not merely 

 numerical, quality as well as quantity of 

 eggs being afifeeted. In witness of this 

 point may be recalled the story of the 

 dying 1903 generation, produced from eggs 

 of the starvelings of 1901 and 1902, which 



would seem to offer conclusive evidence 

 that a famine suffered by the parents works 

 its way into the germ cells so that most of 

 their progeny have but a poor birthright. 

 A more exhaustive study of silkworm 

 fertility and its correlation with anatomical 

 variations and physiological vigor has been 

 begun, and when it is carried to the point 

 of indicating not only how many eggs are 

 laid but hoAV many eggs develop through 

 larval and pupal stages into fertile adults, 

 some clear light may be thrown upon such 

 questions as that which arises concerning 

 the precise ancestry of the survivors of our 

 induced famine and the part these sur- 

 vivors Avill play in race history. 



V. L. Kellogg, 

 R. G. Bell. 

 Stanford UNmERsiTT. 



SOIEl^^TIFIC BOOKS. 



RECENT PSYCHOLOGICAL LITERATURE. 



The lack of an adequate history of the re- 

 markable developments in psychology during 

 the last quarter century has been keenly felt 

 in many directions and not least by the psy- 

 chologists themselves. The task of supply- 

 ing this need is peculiarly difficult. For its 

 successful accomplishment one must possess 

 not only the rare gift of lucid and accurate 

 exposition, but one must also be a competent 

 philosoijhical scholar, with a considerable 

 knowledge of biology in addition to a wide and 

 exact acquaintance with the many phases of 

 psychology itself. The fulfillment of these 

 trying requirements has been in effect essayed 

 by Guido Villa, of the University of Rome.* 

 His book is not entitled a history, but in sub- 

 stance it is such, being an effort to give, in 

 connection with comments upon the work of 

 various authors, a correct impression of the 

 general drift of contemporary psychology. 



It must be admitted that the book is superior 

 to anything else at the moment available. It 

 represents an immense amount of patient en- 



* ' Contemporary Psycliology by Guido Villa ' 

 (translation by Harold Manacorda), Swan Son- 

 nenscliein & Co., London, 1903, pp. xv -}- 396. 



