IM I.I l.\( E OF STARVATION OF INSECTS ON <>l I-1'RINC.. 3! 



by Kellogg and Bell ('04) was exclusively due to the influence of 

 tin- -permato/oa from the starved males, unless the limit- beyond 

 which we "light to expect a noxious influence of the -tar\ .it ion of 

 It in. tie- (in their progeny had been transgressed, ow in g to different 

 decree dt" -tarvation. It ought to be mentioned that in certain 

 species the development of the sexual elements occurs in natural 

 condition- during periods of total physiological starvation. 

 Miescher ~ ascertained that in the salmon which dors ni 

 take any food during the development of its sexual glands its 

 very large ovaries and testicles grow at the expense of niu-i 

 This fact, however, is in no discrepancy with my results as it may 

 be that certain special feeding experiments with salmon it they 

 are practically possible- would, as in moths, elicit in this li-h 

 changes as to the size of the offspring which in natural conditions 

 develops here from "starved" spermatozoa. The generalization of 

 my results obtained in insects to other animals, especially to 

 vertebrates, would be premature. I nevertheless believe that my 

 present contribution will have a certain general interest in regard 

 to the great biological importance of the discussed problem. 



The duration of the larval period does not undergo any essen- 

 tial change in the offspring of starved females nor in that of tin- 

 starved males either. The pupal stage, on the contrary, is essen- 

 tially changed in both cases. My conception of tin- physiology of 

 insect metamorphosis is supported by such behavior of the prog- 

 eny. According to my opinion tin- larval brain elicits by its 

 secretion or secretions the histolysis of lar\al ti ue-, which puts 

 an end to larval life (Kopec, '17 and '22 It .dso checks in the 

 larva the development of the embryonal discs from which the 

 organs of the imago are finally formed in tin- chrysalids ('21 and 

 '23). The prolongation of the larxal lift- and the simultaneous 

 abbreviation of the pupal stage c.m-ed by starvation of cater- 

 pillars has been interpreted a> due to delayed or decreased secre- 

 toric function of the brain. If the prolongation of larval life 

 elicited by starvation of the mother or of the father is due to 

 delayed or decreased production .if the substance by which histol- 

 \ -is of tissues is brought about, no wonder that in the filial 

 generation there is no change in respecl to the duration of larval 

 life: in these experiments the larval organism of the filial genera- 

 tion remains unchanged as to it- preparation for histolysis. The 



