MIMICRY IN BOREAL AMERICAN RHOPALOCERA. 123 



Aristolochia serpentina was formerly much used in human medicine for a 

 variety of ailments and the theory has been built up on its supposed poisonous 

 properties to man and theoretically on the fact that the butterfly imago would 

 be nauseous to birds because its larva fed on this plant. There are ten species of 

 Aristolochia found in the United States and three of them are from the 

 vicinity of Philadelphia. A. serpentaria grows in shady woods, throughout 

 the middle, southern, and western States. The root yields its active principle 

 to cither water or alcohol, and is said to contain one half of one per cent, 

 of an essential oil, about as much resin, a little tannin, and a bitter principle. In 

 ounce doses it deranges the digestion and may cause vomiting, colic, and diarrhea. 



If it takes an ounce of the ground root to have an appreciable effect on the 

 economy of Homo sapiens we can hardly call it an energetic poison and thereby 

 assume that because the larva of the butterfly eats the leaves that the imago 

 would be poisonous or nauseous. Papilio philenor also feeds on other species of 

 Aristolochia that are not known to have any nauseous or poisonous properties. 

 In the north, beyond the range of A. serpentaria, it feeds on A. sipho, the Dutch- 

 man's pipe. It also feeds on Asarum canadense and Ipom&a bonei-nox, a culti- 

 vated plant grown to a considerable extent for its shade and flowers. W. H. 

 Edwards saw a female ovipositing on a species of Polygonum (P. convolvulus?), 

 the black bindweed. 



There is no evidence to prove that P. philenor is nauseous to birds. Neither 

 does it follow that because it feeds on a plant slightly poisonous to man that it 

 would have the same effect on birds. Mountain laurel, Kalmia latifolia, is 

 fatal to man, sheep and some other animals, but is eaten with impunity by deer 

 and partridges. Dr. Barton (12) says in his collections that the Indians some- 

 times use a decoction of the leaves for suicidal purposes. It is said that death 

 has been occasioned by eating the flesh of partridges and pheasants which had 

 been fed on the plant during the winter. Dr. N. Shoemaker has recorded two 

 cases in the North American Medical and Surgical Reporter. Poisoning has re- 

 sulted from eating a pheasant, in the craw of which laurel leaves were found. 

 Here are recorded instances where a plant is poisonous to some animals, including 

 man, and not poisonous to birds. To maintain that philenor is poisonous would 

 require infinitely more evidence than we have at present. Cats are very fond of 

 feeding on the imagos of Protoparce quinquemaculata and Carolina. In this 

 locality the larvse feed on the leaves of the Jimson weed, Datura stramonium. 

 This is highly poisonous to man and to other animals. We can at least infer 

 from this that the imago of the moth does not necessarily have poisonous prop- 

 erties even if the larva does feed on a poisonous plant. 



It is likely that birds feed on insects, other than butterflies, that have fed in 

 the larval or imago conditions on plants that are very poisonous to man, as it 

 is a well known fact that some species feed on the deadliest of plant life. Certain 

 beetles eat aconite root with impunity. It would make an interesting series of 

 experiments to learn whether the imagos of insects that have fed on vegetable 





