DI-.VI l.nl'MI-.Vl A\l I -I RATION OF l.IFK IX 1NSKCTS. IQ 



day after their last moult had retarded pupation, whereas this 

 proces> i~ . i < -leraied \>y starvation of animals approximately 

 since the tenth day after the last moult. 



.v The development of imaginal discs is not the consequence 

 (I' hi-tolyti( al [processes which cause pupation of caterpillars, 

 hut they i.ike place simultaneously from the first days of larval 

 life. Tin- brain causes, probably by its secretion (or secretions), 

 hi-tolysis of larval tissues and it also seems to check in the cater- 

 pillar the development of the imaginal discs. 



4. The prolongation of the larval peruxl in starved specimens 

 may be explained by certain disturbances in the hypothetical 



etory function of the larval brain, which are caused by inani- 

 tion; the abbreviation of the pupal stage may be ascribed to 

 analogous decrease of the influence of this organ, which retards 

 i !) development of imaginal discs. 



5. The average limit of larval growth expressed in the average 

 \\cight of the new-formed chrysulids is in direct pro|M>rtion to the 

 <|ii.mtity of food given and inverse to the prolongation of larval 

 .Hid to the abbreviation of pupal life. (The decrease of weight 

 of caterpillars is larger in cases of longer though more rare fo<xl- 

 intervals than in cases of more frequent but shorter ones.) These 

 rules may be applied only to differently starved whole experi- 

 mental materials, having no application to separate specimens of 

 -i p. irate broods, both starved and control. 



6. The capacity to grow as well as the capacity to undergo 

 metamorphosis exists in starved specimens far beyond the age 

 at which control caterpillars cease to grow and undergo trans- 

 formation. 



7. During long lasting starvation organi-m- get ,n i u-ioined to 

 the abnormal conditions: the rate of gro\\th of tin- caterpillars 

 starved every second day during their whole life becomes in time- 

 considerably greater than that < ! specimen-, .m.ili igic.dly deprived 

 of food since their last moult Inn one. 



M. Hunger death of caterpillar i> probably c.m-ed first of all 

 by exhaustion of reserve sultance-. Natural death of the imago 

 probably is a function of the character of metabolism, as death is 

 delayed by the changed metabolism of intermittent starvation. 



