302 BRITISH LEPIDOPTERA. 



4. In reciprocal pairing the male is able to transmit the ^characters of the species 

 in a higher degree than the female. 



The above cases show that the former influence, viz., that of the 

 older-established species, is the more effective of the two. The 

 sexual prepotency of the male S. pavonia counts for less than the 

 specific prepotency of the female S. spini. The highest effect, of 

 course, is produced when the two influences concur, as in the hybrid 

 of S. spini $ and S. pavonia ?. A further result of the experiments 

 is that, while no female* hybrid was proved to be fertile, there are 

 undoubted cases of fertility in male hybrids. This has been shown 

 by crossing with the females of both parent species, and in one case 

 with a female of a third species (S. bornemanni $ and .S. pyri $ )• 



Standfuss has further proved a close connection between hybridism 

 and a tendency to gynandromorphism, at least among these closely 

 allied Saturnias — spini, pavonia and pyri. Not only were the females 

 sterile or with only the slightest traces of fertility, but a very large 

 percentage of the apparent females of some crosses showed distinct 

 traces of male characters. Strange to say, the cross obtained from 

 S. $ {pavonia X spini) X spini $ (= S. hybr. dixeyi), and that 

 obtained from S. $ {pavonia X spini) X pyri 2 (= S. hybr. 

 schlumbergeri), gave no gynandromorphous examples. Some of the 

 gynandromorphous examples obtained from the other crossings 

 were as follows (Eni., xxxiii., pp. 347 et sea.) : 



1. S. hybr. standfussi. — Of fifty-four imagines bred, twelve are gynandro- 

 morphous. Nine broods produced one gynandromorphous example each, and 

 the tenth brood three. One of these is described as: "A large powerful insect 

 (figured Entom., xxxiii., pi. iii., fig. 3) ; on the upper side the right forewing, 

 the left fore- and hindwings, and the abdomen are entirely of the female coloration, 

 the right hindwing male ; the antennas both nearly male, but with somewhat 

 shorter feathering than usual. The male genital claspers are present in a rudi- 

 mentary form at the end of the abdomen. The underside of the wings and body 

 show male and female characters mixed up with one another, except the right 

 hindwing, which here again is entirely male" (Joe. tit., p. 347). 



2. S. hybr. risii. — Ot eight imagines bred, five were gynandromorphous, 

 probably resulting from four different broods [he. tit., p. 347). 



3. S. hybr. schanfussi. — Of this cross every attempt (9) was successful in 

 producing fertile ova, 207 imagines resulted, and there were ten gynandromorphous 

 specimens, one of which is figured [Entom., xxxiii., pi. hi., fig. 8). It is not 

 known exactly to how many broods these belong nor how they were distributed 

 among the broods. The gynandromorphous example figured is described as being 

 "on the upper side of wings and body predominatingly female, only on the right 

 hindwing, outside the ocellated spot, is a bright orange-coloured patch. . . The 

 antennae are almost entirely $ , and the male genital claspers are well-developed. 

 Beneath male and iemale characters are indefinitely mixed, only the right hind- 

 wing is entirely ? " (toe. tit., p. 348). 



Of some 4000 hybrids that Standfuss has bred, he notes (Ent., 

 xxxiv.. p. 11) having had only two gynandromorphous primary hybrids. 

 One of these was an example of S. hybr. emiliae (bred in 1897J, the 

 other a S. hybr. bornemanni (bred in 1898). On the other hand, he 

 obtained 27 gynandromorphic secondary hybrids out of a total of 

 282. He, therefore, concludes that "the percentage of gynandro- 

 morphic specimens among primary hybrids is infinitesimal compared 

 with the occurrence among secondary hybrids. It is, however, 

 higher among primary hybrids than among individuals of pure 

 specific origin." Discussing the matter further, he concludes (ioc. 

 cit., ]). 13) that "the degree of fertility of a form stands in direct 

 connection with the percentage of gynandromorphic individuals in 

 its offspring ; the greater the fertilit y the smaller the percentage of 



* This has not held altogether. A ? schaufiissi has since been mated with a <T 



