12 SCIEXCE PROGRESS. 



Staudinger O. zoragena) resembles a large O. hemigena. 

 Accordino- to Kroning: the monorrel issue are fertile inter se, 

 but quickly degenerate in size and vitality. This of course 

 may be due to other causes than their mixed origin. 



4. Spilosonia mendica CI. S Sind do. var. rustica Hb. ?. 

 The larv^ae were nearly always formed within the egg ; but in 

 some broods not one, and in others only from 8 to 1 2 per 

 cent, hatched. In one case, however, as many as 93 per 

 cent, of the eggs gave living larvae. All the broods suffered 

 severely from disease. The perfect insects, which did not 

 show much variation, diverged only slightly in appearance 

 from var. rustica. The males were mostly light-coloured, 

 as in that variety, and the darkest of them were far lighter 

 than any male of ^. mendica. 



5. 5. mendica var. rustica S and 5. 77tendica ? . The 

 reciprocal cross, which failed with Standfuss in consequence 

 of an epidemic among the larvae, was obtained by Caradja. 

 Pupae sent by him to Standfuss gave thirty-one perfect in- 

 sects, seventeen being males and fourteen females. These 

 were more variable than the former cross-product, but on 

 the whole inclined towards var. rtistica.^ 



It is observable that in this case of reciprocal crossing, 

 the influence of the females appears to be equal to if not 

 greater than that of the males. This shows that the 

 generalisation as to male prepotency founded on the case of 

 the Saturnias is not of universal application. It will be 

 remembered also that the issue of one of the pairings 

 between C, dominida $ and var. persona ? showed female 

 prepotency, though the general result in the case of this and 

 the reciprocal cross tended in the opposite direction.- 



Standfuss considers that the present experiments with 

 species and their local races favour his view as to the 

 superior influence of the phylogenetically older form. 



Aberrations. Some very remarkable facts are recorded 



^ This corresponds, as has been pointed out by Mr. South, with the 

 result obtained by Mr. Adkin, who effected the same cross in 1889. Vid. 

 Entomologist, for August, 1897, p. 206; Proc. Ent. Soc. Lo?id., 1890, 

 p. xl. 



2 See also p. 199, infra, note. 



