190 



SCIENCE 



[N. S. Vol. XLII. No. 1075 



the soldier from honorable parenthood. In 

 addition to abundant records from Europe and 

 America, we have the following facts from 

 Japan. 



The war between China and Japan occurred 

 twenty years ago. It involved the destruction 

 of a large number of picked men of Japan and 

 a corresponding reduction in the virility of the 

 nation. The effects of the loss on the succeed- 

 ing generation can not be felt until the chil- 

 dren born in 1895 attain their majority. These 

 results can be measured only in the reduced 

 stature of the incoming conscripts and in the 

 proportion of exemptions from military service. 

 " Like the seed is the harvest." The new 

 generation takes the quality of those men and 

 women who were its actual parents. Those 

 whom war has destroyed, in general the 

 stronger and the best developed physically, are 

 not represented. 



According to the Asahi of Tokyo, as trans- 

 lated in the Japan Chronicle, the number of 

 available conscripts in Tokyo for this year is 

 9,235, instead of 9,981. For a number of years 

 there had been a steady increase of about 800. 

 This falling off of 1,546 marks a decrease of 

 over 16 per cent. In Kanda, the most densely 

 populated ward of Tokyo, the decrease was 22 

 per cent. 



In the whole nation, a slight increase of 

 conscripts has taken place, 482,965 as against 

 472,147 of 1914. But this rate of increase 

 (9,000) is only from thirty to fifty per cent, of 

 the normal, which for years has ranged from 

 20,000 to 30,000. 



More important than the reduction in num- 

 bers is the lowering in quality. In Kanda in 

 1914, twenty-four per cent, of the conscripts 

 were passed as " strong," while in 1915, the 

 percentage was thirteen per cent. (83 out of 

 635, instead of 194 out of 813). A much 

 larger percentage of those sent to the barracks 

 were of the " average " class. 



The birth-rate in Japan, as in every other 

 nation, declined in time of war, to rise again 

 at its conclusion. 



This decline of physique is a matter of con- 

 cern to the military authorities of Japan, but 

 they optimistically hope that it is of a tempo- 



rary nature. The Asahi concludes that " most 

 of those who underwent conscript examina- 

 tions this year were born during the war and 

 therefore are sons of those too old or too weak 

 to go to the front, and so it is no surprising 

 thing if the conscripts of 1915 are of excep- 

 tionally delicate constitution." 



David Starr Jordan 

 July 24, 1915 



SCIENTIFIC BOOKS 



Key to the Families of North American In- 

 sects. By Charles T. Brues and A. L. 

 Melander. Boston, Mass., and Pullman, 

 Wash., published by the authors, 1915. 

 Most modern works on entomology contain 

 keys or tabular synopses, intended to facilitate 

 the determination of families, genera and 

 species. It is the experience of those who have 

 classes in entomology that these keys are on 

 the whole unsatisfactory, being frequently in- 

 complete, incorrect or unintelligible. The most 

 noteworthy exception is found in Williston's 

 " Manual of North American Diptera " (1908), 

 which, considering its scope, could hardly be 

 improved. One who has constantly used 

 Williston's book for a number of years be- 

 comes convinced that it is possible to prepare 

 keys which will in nearly every case enable 

 the student to determine the genus of the in- 

 sect before him, especially when he has also the 

 aid of numerous outline figures. It is really 

 astonishing how soon a clever student will 

 learn to use works of this kind ; at Boulder we 

 find that students using an illustrated table of 

 Rocky Mountain bees can frequently determine 

 correctly as many as four genera in an hour, 

 in spite of the fact that the insects and the 

 kind of work are new to thfem. Exceptional 

 students do even better than this. 



The method having proved so satisfactory. 

 Professors Brues and Melander thought it 

 worth while to prepare a key to all the families 

 of North American insects, illustrated, like 

 Williston's book, with many outline figures. 

 Thus we have for the first time a complete 

 synopsis of the families, whereby the student 

 may find the place in the taxonomic system of 



