14 STEFAN KOPEC. 



pupa 1 . The chrysalids were weighed from i to 24 hours after 

 pupation, control weighings having proved that the weight of 

 pupa 1 decreased in my broods during this period only from 0.18 

 per cent, to 0.33 per cent. The limits of fluctuations in the weight 

 of pupa.' are recorded in Table I., together with their average 

 values. On Table III. we see moreover the average weight of 

 "starved" chrysalids of each brood calculated in percentages of 

 the average weight of control chrysalids of the same sex and 

 brood . 



On comparing the data of series C, D and E we see that the 

 weight of chrysalids decreases more and more in proportion as 

 the number of fasting days increases. Assuming in general that 

 the number of feeding days in separate series corresponds to the 

 quantity of food which has been taken, we may say that the 

 weight of pupa^ is in direct relation to the quantity of food 

 consumed. If we also take into consideration the data of series 

 F in comparison to analogous items of series D, we draw the 

 conclusion that the average decrease of chrysalids due to inani- 

 tion of caterpillars is larger when the feeding intervals are longer 

 though less frequent. As it was pointed out, the prolongation of 

 the stage of caterpillar and the abbreviation of that of pupa 

 increases in proportion as more and more intense starvation has 

 been applied. Consequently, the weight of the pupa? the cater- 

 pillars of which had been starved is in inverse relation to the 

 prolongation of the larval period as well as to the abbreviation of 

 the stage of chrysalids. Adopting the ratio of the pupal weight 

 to the duration of larval life as the approximative measure of the 

 rate of growth, we can infer from Tables I. to III. that this 

 rate decreases in proportion as more and more intense starvation 

 has been applied and in relation to the distribution of the feeding 

 and fasting days (Series F and D). The above-stated principles 

 refer to separate series of experiments but not to separate speci- 

 mens, either control or starved, in one brood. I have often ob- 

 served that although the processes of transformation lasted in 

 the control or in the starved material in every brood several 

 days, the heaviest and the lightest caterpillars underwent pupa- 

 tion the same day, sometimes the first and sometime:- not until 

 the last day, although the one was two- or threefold heavier than 

 the other. The same may be said as to the duration of pupal 



