203 



opinion, I should say I believe it possible that Columbia may be a 

 hybrid, perhaps of Cecropia and Prometliea, and I will state what 

 I believe to be in favor and disfavor of this conjecture. In favor 

 would be the circumstance that it is very improbable that such a 

 large species should occur so rarely, while the large number of Lepi- 

 dopterologists eager to secure this treasure, operates against the idea 

 that it was overlooked. 



The conjecture that Columhia is a hybrid, would not be worth 

 mentioning, if there did not exist similar cases recorded by the 

 most prominent authorities. Of course I speak only of cases of 

 hybrids as imagos or caterpillars, from which images, when bred, 

 have been collected in the open fields. The facts just at hand (I 

 have no doubt that more are published) record caterpillars of hyb- 

 rids of Saturnia Carpini and Spini, found in Austria according to 

 Lederer; caterpillars of Sphinx Epilobii, a hybrid of S. Yespertilio, 

 and Euphorbiae, being found in France according to Kambur; 

 in the same country are found also caterpillars of Sph. vespertili- 

 oides, the hybrid of S. vespertilio and S. Hippophaes according to 

 Boisduval and Lederer. 



The imago and caterpillars of SjjIi. PMUupliorhiae, hybrids of 

 Sph. Eupliorbiae and Galii, have been found near Berlin, in several 

 specimens. Hybrids of Zijgaena Trifolii and Filipeiidulae were 

 found in the imago state in England, hybrids of Colias Eclusa 

 and Hyale, of Lycaena Adonis and Alexis, of Hipparcliia Arcania 

 and Hero, of Coenonymplia Faniphihcs, and Iphis, of Vanessa Urti- 

 cae and Atalanta are recorded from different countries. 



Artificially raised hybrids are recorded for Smerinthus ocellatus 

 and 2^opuU, Saturnia spini and Carpini; Saturnia sjjini and pyri 

 Platypteryx falcula and curvatula, Dicranura vimda and erminea, 

 Zygaena filipendulae and minos, while numerous facts observed in 

 the Garden of Acclimatization in Paris by Guerin with Attacus 

 Cynthia and Arrindia, and other species of silk-worms, undoubtedly 

 prove the possibility of inter- breeding among certain species of the 

 genus Attacus. Mr. Riley, Rep. Ill, 170, succeeded in obtaining 

 eggs from A. cynthia $ and Cecropia ? , and from Cecropia <5 and 

 Polyphemus ? , but the eggs did not hatch. 



Comparing the hybrids known between vertebrates, and some 

 occur not rarely, and even regularly, we find them mostly recorded 



