SOCIETIES. 167 



other Holanaceae, and had but recently acquired its preference for its 

 present food-plant. With regard to Splvinxcuncolndi, Mr. Prout thought 

 there was much room for difference of opinion, the larva and pupa 

 being so rarely met with, whilst the imago appears much more 

 commonly than the actual rarities of the family. He thought it was 

 impossible to look upon it as a mere "casual" visitor or imported 

 species. Of the 2nd division, Mr. Prout said that Sphin.v pinaiitri 

 " now occurs annually in a certain restricted district in Suffolk, and 

 the question is — Is it indigenous there, or how and when was it 

 introduced ? The two Dcilephilas probably do not occur annually in 

 any part of the British Isles." In the 8rd division, Mr Pro at said it 

 should be borne in mind, in forming our theories with regard to 

 Choemcawpa nerii, that some of the specimens have turned up in the 

 metropolis, and that it has never been taken otherwise than singly. ( '. 

 celerio is one of the most widely distributed of all Lepidoptera, ranging 

 over Asia, Africa, Australia and Southern Europe, and feeding almost 

 exclusively on the vine. Mr. Prout thought that these two Avere 

 obviously not genuine natives here. Proceeding to mention one or 

 two curious circumstances connected with the moths, Mr. Prout said 

 that the majority of records for all the species, except S. pinastri, 

 belonged to the late summer or autumn months, and that where 

 records for the spring or early summer were found, the specimens 

 were generally worn, so that they had been regarded either as 

 immigrants, or as hybernated examples. Yet in their own proper 

 habitats nearly all the species appeared to have also a genuine summer 

 brood, Mr. Prout further noted that the great preponderance of our 

 " casual visitors " amongst all the Lepidoptera, as well as those species 

 which, though never entirely absent, occur occasionally in enormously 

 increased numbers, appear with us at the same season of the year, 

 though the majority again have also a summer brood in their true 

 homes. Again, there was the yet further coincidence that a large 

 number of these species have been suspected either of hybernating or 

 of appearing pretty continuously throughout the winter in warmer 

 climates, and certainly several of them could be brought to additional 

 broods in the winter when reared in captivity. And finally, there was 

 evidently something abnormal about the conditions of these autumn- 

 emerged specimens ; the females were frequently either partially or 

 entirely sterile, or if eggs were laid they could not be brought 

 through their transformations ; the larvtB usually seemed in- 

 capable of hybernating, and perished unless they could be fed 

 up in artificial warmth. In the face of these coincidences Mr. 

 Prout was disposed to conjecture that there must be some one 

 broad general principal underlying and governing the migratory 

 propensities of these species, and to account for the comparatively 

 trivial variations of habit in matters of detail by reference to some 

 merely secondary climatic or phytophagic influences ; and that such 

 principle, if existing, must assuredly be one of no mean biological im- 

 portance. Mr. Nicholson gave some interesting details with regard to 

 SpJiin.r pinastri. He had read a note in the Kntoninhiiji^t to the effect 

 that it fed on cedar. He thought that immigration was responsible 

 for the appearances of Ih'ilephila nipJtorhicu', 1). Uvornica, J>. t/alii and 

 C'huerocaiupa celerio. Mr. Bacot remarked that these moths were all of 

 one form, with large eyes, strong wings, &c., an argument in favour of 



