Scudder.] 



118 



[Oct. 22, 



the ratio of the pupal to the larval period, or directly proportional to 

 the ratio of the larval to the pupal period." 



Mr. Meldola attempted to test this theory by tabulating the state- 

 ments of Mr. Edwards concerning the duration of the stages in the 

 different polymorphic forms of Ajax, and he found ; 'that there was a 

 relationship, but exactly the reverse of that which would be antici- 

 pated from the conclusions previously set forth." 



The three forms of Ajax have been called by Mr. Edwards WalsJiii, 

 Telamonides and Marcellus, and these increase in size in regular 

 ratio and succeed each other in season in this order; the following 

 table represents the duration of the several stages, and is taken by 

 Mr. Meldola from Mr. Edwards' work : — 





Walsliii. 



Telamonides. 



Marcellus. 



Eggs. 



7-8 days. 

 4-5 " 

 4-5 " 



Larva. 



22-29 days. 

 15-18 " 

 12-19 " 



Chrysalis. 



14 days. 

 11-14 " 

 11-14 " 



Total. 



43-51 days. 

 30-36 " 

 27-38 " 



The next table is Mr, Meldola's attempted tabulation of the facts 

 by which he comes to the above conclusion : — 



Name of variety. 



Ratio of mean piipal Ratio of mean larval 

 to mean larval period, to mean pupal period. 



Mean 



expanse tf. 



Walsliii. 



Telamonides. 



Marcellus. 



11:1=0.757 

 Iff = 0.806 



1.821 



2Ju_5 

 14 



if;|=z 1.320 

 lf;| = 1.240 



2.70 

 3.00 

 3.35 



" It is here seen," says Mr. Meldola, " that the size of the variety 

 is directly instead of inversely proportional to the ratio of the pupal 

 to the larval period, and vice versa. 1 ' Unfortunately for this conclusion, 

 the figures given by Mr. Edwards, or their reduction by Mr. Mel- 

 dola, refer in each case to the progeny of WalsJiii, Telamonides and 

 Marcellus, and do not bear upon the question ; in every instance 

 given in the tables the progeny or resultant is Marcellus; Walsliii and 

 Telamonides are the produce of wintering Chrysalides, and therefore 

 by Mr. Meldola's rule, should be, as they are, smaller than Marcellus, 

 which, on the other hand, is always the result of short lived sum- 

 mering chrysalids ; unless, however, some unknown factor plays a 

 part, Telamonides should be smaller than Walsliii, because produced 

 later in the season, from wintering chrysalids; but here the opposite 

 is the truth. 



