438 C. H. TURNER 



folds connected with the spiracles were the cause of the sound. 

 Unless the reviewer entirely misunderstands Aubin's words and 

 illustrations, his apparatus is not connected with the spiracles. 

 It does, however, seem strange that Aubin makes no mention 

 of the work of Pemberton* which was reviewed in this journal 

 about three years agof. Pemberton, as a result of his exper- 

 iments, insisted that there is no spiracular voice in insects 

 and that the high-pitched notes of the Diptera and the Hymen- 

 optera are caused by the striking of the bases of the vibrating 

 wings against the sides of the thorax. Apparently he over- 

 looked the ridges against which the wings impinge and the 

 vibratile membranes connected with these ridges. 



DURATION OF LIFE 



Baumberger (4) found that, when exposed to constant tem- 

 peratures, the longevity of insects varies, approximately, in- 

 versely with the temperature; when exposed to variable temper- 

 atures, a high or low temperature followed by medium tem- 

 peratures favors a lengthening of life; exposure to a medium 

 temperature at the beginning shortens life. 



By crossing a short-lived strain of the fruit-fly (Drosophila 

 ampelophila) with a long-lived strain, offspring were obtained 

 which were longer lived than either of the parents. In the 

 second generation some reverted to the short-lived condition. 

 He thinks there is a physiological connection between the length 

 of life and the coming into maturity of the germ cells. 



Sanderson and Peairs (76) give a table showing the relation 

 of temperature to the duration of life. The table was compiled 

 from more than 400 separate experiments involving 390,000 

 individuals. 



Phillips and Demuth (70) assert that the length of life of 

 bees varies inversely with the amount of work they do; hence, 

 to secure vigorous bees for the spring, the work to be done in 

 winter should be reduced to a minimum. 



Phil and Nellie Rau (71) have made extended studies of the 

 longevity of the following Saturnid moths: Philosamia cynthia, 

 Telea Polyphemus, Callosamia promethea, Samia californica, and 



* Pemberton, C. E. Sound Producing Diptera and Hymenoptera. Psyche, 

 vol. 18, pp. 82-83, 1911. 



t Jour, of Animal Behav., vol. 2, p. 396, 1912. 



