THE STATE ENTOMOLOGIST. 161 



escape from their cannibal foes, that Mr. H. W. Bates, the English 

 naturalist, who spent eleven years in the Valley of the Amazon River ? 

 studying the natural history of the insects of that region, where this 

 particular group of butterflies is very copiously represented, declares 

 that he never saw a single one of them attacked by any cannibal foe 

 whatever, whether bird, or Dragon-fly, or lizard, or Asilus-fly. 



It is therefore reasonable to assume that their peculiar odor ren- 

 ders them unpalatable to animals of prey. We have seen that the Arch- 

 ippus butterfly enjoys an almost perfect immunity from the attacks 

 of predaceous animals, consequent, in all probability, upon this pecu- 

 liar odor which attaches to it both in the larval and perfect states. 

 In this case the supposition is even strengthened by the fact that the 

 only parasite known to attack it is a Tachina-fi.y, belonging to a fami- 

 ly which is notoriously defiant of strong odors, the larvae often rioting 

 in filth and the flies many of them known to be especially attracted 

 to such odors. 



Now there is another large group of butterflies, known as the 

 Pieris family, to which the white cabbage butterflies belong, which 

 were mentioned in my last Report (pp. 104-110.) This group differs 

 widely in structure from the Danais group, and is represented by 

 many species in the Valley of the Amazons; but instead of the spe- 

 cies being exceedingly abundant in individuals, as in the case of those 

 belonging to the Danais family, it is quite the contrary; the propor- 

 tion between the number of individuals belonging respectively to 

 two of the commonest genera of either group (Leptalis and Ithomia) x 

 being only 1 to 1000. Hence, it is reasonable to infer that this group 

 must be much persecuted by cannibal foes, and such has been found 

 to be the case.* 



The colors found in the species of the Danais family are red, 

 yellow, orange, white and black; while only thelast two colors obtain 

 in the Pieris family, the white being sometimes tinged with green- 

 ish yellow. So far so good. We see flitting about in the great Val- 

 ley of the Amazons, vast swarms of long winged butterflies, gorgeous- 

 ly dressed in red, orange, yellow, white and black; and certain short- 

 winged butterflies, in very much smaller numbers, whose proper liv- 

 ery is but the plain black and white that befits a funeral. We see 

 the former enjoy an entire immunity from the attacks of all preda- 

 ceous animals, and the latter snapped up by every hungry bird, Dra- 

 gon-fly or Asilus-fiy that happens to come across them. Will it be 

 believed, now, that there are certain particular species of the homely, 

 much persecuted, short- winged group, that assume the livery worn by 

 certain particular species of their gaily dressed compatriots, and ac- 

 tually even copy their elongated wings ? Yet such is the indubitable 

 fact. In the Memoir of Mr. Bates, already referred to, will be found 



-These facts were first brought to light about nine years ago, by Mr. Bates, in a most inter- 

 esting and valuable Memoir, published in the Transactions of the Linnoean Society, (Vol. XXIII., 

 p. 495.) 



S £—11 



