346 THE ENTOMOLOGIST. 



The chief points noted by observing the development of these 

 numerous hybrids were as follows : — 



1. The secondary hybrids were not only produced by pairing 

 primary male hybrids with females of the parent species, but 

 also with the females of a third species. 



2. A larger percentage of the broods of crossings of these 

 primary hybrids with females of the phylogenetic oldest of its 

 parents developed, than with the females of the younger. 



The results concerning crossing with the third species are 

 too incomplete to form any opinions as to fertility. 



3. The resulting brood shows in general the same charac- 

 ters as in the primary hybrids, in biological and physiognomical 

 respects, but with a larger individual variability.'^ A tendency 

 was shown to follow the line of development of the phylogenetic 

 older form of the two, and in the three species the phylogenetic 

 oldest form. 



4. In a lesser degree there is to be found in some male 

 individuals a capability and inclination to individual develop- 

 ment in new directions within a narrow limit. 



5. Besides males capable of limited and individually varying 

 degree of reproduction, and females mostly sterile, or only 

 fertile to a slight degree in the hybrid No. 13, there appeared 

 among certain secondary hybrids a relatively large number of 

 gynandromorphous specimens, in various crosses and in varying 

 proportions (PI. III. figs. 3 and 8). 



6. The physiological affinity of the secondary hybrid males 

 and also of the somewhat fertile females to the related types 

 could not yet be ascertained, so that nothing definite can be 

 said about it. An increase of fertility, compared with the male 



these hybrids were both very large females of the Dalmatian type of S. 

 pavonia. The great size of these insects is certainly due to the greatest 

 extent to this origin, as only one-eighth of the S. pyri blood of the great- 

 grandmother remains. In general all these creatures have the appearance 

 of large light coloured S. pavonia males of the Dalmatian form. 



' In order to show these individual differences, we represent on PI. III., 

 figs. 1, 2, and 3, three insects of the same brood. Figs. 1 and 2, males ; and 

 fig. 3 a gynandromorphic specimen from crossing No. 10. They are bred 

 from a large male of crossing No. 9 and a female S. pavonia from Ziirich. 

 The two males show great differences in wing structm-e and coloration. 



When the much larger Dalmatian S. pavonia was used for crossing 

 instead of the Zurich form, the resulting individuals of this brood, No. 10, 

 showed still greater differences in wing measurement and coloration (see 

 footnote 1), but they are such large specimens that it was impossible to 

 figure them on account of room. 



Further, PI. III. figs. 6, 7, and 8 are also three brood companions, two 

 males and a gynandromorphic specimen, from crossing No. 13. 



Here also the two males, figs. 6 and 7, show great differences of size, 

 also important differences in coloration. The original of fig. 6 has dull 

 orange hind wings, whereas No. 7 has a pale rose colour tone, so that the 

 colour differences of these two brothers are very great. For the gynandro- 

 morphic specimens, figs. 3 and 8, see footnotes 8 and 9. 



