!>1 \ l.l.nl'MI.N I AND I >I RATION OF LIFE IX INSE< fS. ~ 



period was smaller than the prolongation of the larval Mage, we 

 must draw the concln-ion that total deprivation of food of cat- 

 erpillars e\ ery -ccond day has^ considerable po-itive effect on 

 the total duration of their life from hatching until death. The 

 prolongation of i In- whole developmental period amount- here 

 in tin- average of broods in males to 16.5 and in female- to 20.4 

 days, or in penvntavie-; relative to the duration of life of control 

 -peeimeii- in males to 24.2 per cent, and in females to JO.O per 

 -nt. 



The .ibove results find complete confirmation in my farther 

 lomp.tr.itive experiments in which inanition of various intensity 

 \\.i- applied (Aeries C, D and E). In these experiment- cater- 

 pillar- \\ere used from I to 12 hours after their last moult but one. 

 In -cries C food was administered two days, the third day the 

 ei- were starved (starvation lasting one day every third d \ 

 + + +-) In series I) the animals were again de- 

 pri\ed of food every second day (starvation lasting one day 

 e\cry second day + *+ H ) and the caterpillars of seru- 

 /. ueie depiived of I'CMM! i \\ o days and ate only every third day 



irvation lasting twodays every third day + + + -). 



I in tin- absolute figures of Table II. as well as from I he 

 ptn tillages in Table 111 \\e ma\ infer that the duration of t he 

 lar\al period undergoes also, in these starved animal- coii-idei- 

 able prolongation (cf. analogous results obtained in silk-\\onn- 

 l>\ Kello-c .md Bell, '04 b), simultaneously with abbreviation <>t 

 the pupal stage. These changes become more and IIH-M 

 marUable in proportion as inanition in . the\ are larger in 



-erie- /' than in series C' and the large>t in -eiit- /.' in \\hich the 

 fa-ting da\'s were the most numeron-. Al-o in the-i . ..mpara- 

 ti\'e experiments the prolongation of the larxal life \\.i- greater 

 than the abbreviation of the pupal period, \\hile the duration of 

 the imaginal life n-mained unchanged. Hence it follows that 

 the total duration of the life of the insects from the beginning 

 of the experiment till death of the moth, i- more and more in- 

 creased in proportion as inanition increases within the limit- ot 

 the experiments. The duration of development from the la-t 

 moult but one till the emergence of the moth underwent in the 

 average of broods a prolongation ic.ilcul.ited in percentages of 

 the average duration of such control period- 1 \\hich in the male- 



