DEVELOPMENT AND Dl RATION OF I.1FF IN INSF.i PS. 15 



life in regard to the weight of separate chrysalids of one brood. 

 The problem ari-e- whether the capacity to grow i- checked 

 by age of the .uiimal. Such limits in rats have been adopted by 

 Aron ('12 .ind l.itely by Jackson and Stewart ('20), in contra-t 

 to < )-borne .ind Mendel 14) who are inclined to the opinion 

 ili.it the i.ip.tcity to -ro\\ is exhausted by mere growth, without 

 ,rd to the factor of time. In series B of my experiment - the 

 rpillar-. depi i\ cd of focxl intermittently for 2O days since their 

 hatching. \\eighed the twenty-first day in separate broods, on the 

 avei :ily 7.6, 3.6 and 5.0 mg., while control individuals of 



tin -.line brood- had the mean weight of as much as y^>, 45.5 

 .ind 40.} in-. The starved specimens fed daily since the twenty- 

 tir-i day attained and partly exceeded in time the weight .md 

 -i/e of ei >MI ml caterpillars (cf. weights on Table I. ami III. \- 

 iii thi- series the processes of metamorphosis of original!) -Mixed 

 aierpillars were retarded and as, on the other hand, caterpillar- 

 ha\ e grown until the end of their larval life, it ought to be interred 

 that in t hese animals the capacity to grow is not -npprc--eil at a 

 period at \\liich caterpillars normally cease to gn>u . M"ie..\er, 

 it may be concluded that pupation also may take place mm h 

 be\(nd the age at which the control specimens undergo pupa- 

 IIMI. But the inference that the capacity may not at all be 

 limited by the age of animals ought not to be drawn from Mich 

 results. 1 1 is possible that the rats experimented upon \>\ Mendel 

 and < )sborne as well as my caterpillars would lose the capacity 

 to obtain the weight and size of control -pecinu-n- it they had 

 been kept at maintenance or starved c\cii a feu da\- longer. 



4. ;\D\ri \1ION OF OR( IAN ISMS TO S I \ \< \ \ IK \ . Si All l\l \I \KK- 

 ON TIIF. PK()l;l IM n| I )| \ Ml. 



The \\eiijit of pupa- from M-rii - .1 in which >tar\ation la-ting 

 01 H- dav e\er\ p second day, + + + -, \\a- a|>plied in cater- 

 pillars during the whole lar\al life i- exideiitly different from 

 that of series I) in \\hich older -pecinu-n- after their la-t moult 

 but one were subjected to the same -tarvation (cf. Table I.). 

 We see that or^ani-m- may in time ^et accu-tomed to the detri- 

 mental effects of -tarvation. which prevent the animal from at- 

 taining its normal weight: the compari-on of the limits of indi- 

 \idual lluct nations -hown on Table I. point- to the coin ln-ion 



