356 THE INFLUENCE OF LIVING SDKROUNDINGS. 



gentleman's house bred two years in succession. The processes 

 of such attempts at hybridisation have not unfrequently been 

 detected. Thus, G. Koch observed the union of Zygcena peuce- 

 dani with Zygcena trifolii, of Zygcena minos with Zygcena loni- 

 cerce and of Smerinthus populi with Smerinthus ocdlata. A. 

 Meyer detected that of various species of Phryganidce ; Peragallo 

 that of Luciola lusitanica with Ragonycha melanura ; Kuenckel 

 that of Strangalia melanura with Leptura livida ; Gerstaecker 

 that of Tipula oleracea with Pachyrhina scalaris. Heynemann 

 also tells us that Lymncea stagnalis and Lymncea auricularis have 

 bred together. Of course the question remains unanswered as 

 to whether in all these cases the union led to the production of 

 offspring ; but the mere fact that in a free state of nature such 

 attempts at hybridisation are certainly made, renders it in a 

 high degree probable that they may frequently lead to such a 

 result, and we can no longer doubt the possibility of hybridisa- 

 tion in a free state of nature. 



Now, I began by saying that such hybridisation might be 

 one of the means employed by nature for originating new forms, 

 that is to say, for producing offspring, and, moreover, fertile off- 

 spring, which varied from their parents in form, colouring, and 

 other characters, thus offering to Selection fresh material to ex- 

 periment upon. To justify this statement it will be sufficient 

 to examine one or two of the above-quoted instances rather 

 more minutely. 



The hybrid cockatoos which I have mentioned were distin- 

 guished from their parents very conspicuously, for while one of 

 \ these was white and the other ros2-coloured, both the broods of 

 yoiing birds had large orange-coloured tufts. All the hybrids 

 of fishes spoken of by Siebold display a peculiar mixture of the 

 characters of both parents, besides others which cannot be 

 referred to either with any certainty. The descriptions given 

 by many systematic naturalists of recognised ability, of various 

 hybrids as distinct species, prove that in these cases as, for 

 instance, in Felis torquata, Anas bimaculata, and others cha- 

 ractei'S occur which do not positively belong to either parent. 

 The hybrid between the masked pig and the Berkshire pig was 

 black with white feet, and the hybrid bear born at Stuttgart, 



