1912.] NATURAL SCIENCES OF PHILADELPHIA. 141 



teristics from both himself and the child's mother, and should, 

 thereby, be able to start forward on his new career under the most 

 favorable physical and moral circumstances. The idea greatly 

 reenforces the natural instinct, sometimes dulled, or even wholly 

 perverted, towards family life, which has long been considered the 

 chief promoter, if not the very foundation, of morality. 



Evidently, natural history supplies the clearest principles and 

 most cogent motives for morality; and further and more precise 

 knowledge of the instinct of animals in their natural state (not so 

 much in the artificial, pampered, domesticated condition) may 

 sometimes yield important guidance towards detailed rules of con- 

 duct. Special applications of the principles (not according to mere 

 speculations, but to observed facts) are to be worked out, also, by 

 courts of justice, aided by schools, colleges and learned societies, 

 as the tendency has been for hundreds of years, especially among 

 the more logical nations. 



Natural history, then, teaches through the thorough unity and 

 consanguinity of all living things, that, besides sympathizing with 

 them all and perceiving how much may be advantageously learned 

 from them as our relatives and congeners, we must not merely 

 struggle with them and with each other for existence and the survival 

 of the fittest, to the benefit of the race, but for the same reason, 

 equally must aid in the protection of our weak immature ones, 

 strictly our second selves, and by this habit, or instinct, maintain 

 complete morality, under the strongest incentives, unerringly and 

 inflexibly guided by natural selection. 



Jacques Loeb, M.D., Ph.D., Sc.D.: " Experiments on Adaptation 

 to High Temperatures." (No abstract.) 



Henry Skinner, M.D., Sc.D.: ''Mimicry in Butterflies."* 



It has been stated that some of the females of the American species 

 of Papilio have gradually changed their appearance to resemble 

 Papilio philenor, a species which in the larval stage feeds on Aris- 

 tolochia serpentaria , a plant having a root poisonous to man. It is 

 therefore contended that in the imago stage this butterfly is nauseous 

 or poisonous to birds, and that +he birds, mistaking the edible species 

 for philenor, avoid them. 



The objections to this hypothesis are, that the records of birds 

 eating butterflies are very meagre, and there is no evidence to prove 

 that philenor is nauseous or poisonous to birds. 



It has been shown that plants may be poisonous to man, to some 

 other animals, and yet may be eaten by birds with impunity. 



The species said to be protected by their resemblance to Papilio 

 philenor are different in appearance in the two sexes and it is the 

 females that show this mimicry. These sexual differences are 

 termed antigeny and it is not unusual in the butterflies. It is due 

 to some general law and not in certain instances to so-called mimicry. 



