July— August iSSS.] 



PSYCHE. 



79 



THE MEANS EMPLOYED BY BUTTERFLIES OF THE GENUS 

 BASILARCHIA FOR THE PERPETUATION OF THE SPECIES. 



BV SAMUEL HUBBARD SCU 



The power of reproduction conceded, 

 the universal instinct for self-preserva- 

 tion is the fundamental and controlling- 

 principle b}- which the perpetuation of 

 any kind of animal is successfidl}' 

 reached. The uncontrollable maternal 

 instinct of self-sacrifice existing in some 

 animals alone overmasters it, and this 

 exists only in the higher animals, which, 

 compared with the great mass, are but 

 few in number ; and is then in most 

 cases called into play only when the 

 creature's life-work is nearly finished. 

 No such instinct occurs among butter- 

 flies, nor is in any way likely to be 

 found, so that "self-preservation" and 

 "perpetuation of the species" are here, 

 at least through all but the closing days 

 of life, practically equivalent terms. 

 The "struggle for existence" in the 

 species and in the individual are largely 

 convertible terms. 



This struggle is the perpetual inheri- 

 ance of the individual. Tiie individual 

 inherits alike its structure and its habits 

 of life, which latter are very largel}', 

 perhaps almost absolutely, dependent 

 on its structure ; its tastes and its pro- 

 pensities, its fears and its devices to cir- 

 cumvent its enemies ; all its instincts, 

 which are to a great extent, possibly 

 whollv, the entailment of ancestral 

 habits ; its ver}' attitudes, whether at 

 rest or in motion. Its advantages and its 

 disadvantages are thus alike its legacy ; 



DDER, CAMBRIDGE, MASS. 



SO too the peculiar means it employs to 

 disembarrass itself of these disadvan- 

 tages. This is especially and more 

 immediately true of the insect in its 

 earlier stages, where freedom to change 

 the immediate surroundings is exceed- 

 ingly limited or altogetlier impossible, 

 except so far as there is foresight, or an 

 instinct marvellously akin to foresight 

 on the part of the creature in an antece- 

 dent stage. 



It is of more than usual interest to 

 study the means of self-preservation in 

 the genus Basilarc/iia, since there is 

 hardlv another genus of butterflies 

 where throughout its entire life the in- 

 sect is apparently so exposed to its 

 enemies. They are all, of their kind, 

 conspicuous objects even to our dull 

 eyes, and more than that they are, with 

 the exception of the clirysalis, always 

 found in unusually conspicuous situa- 

 tions. How then do they manage to 

 escape their keen sighted foes, the birds, 

 or their wakeful, indefatigable, persis- 

 tent enemies among the insect tribes, — 

 ichneumons, ants, wasps, flies, mites, 

 and spiders.? 



Take first the egg-stage. Every one 

 who has attempted to rear butterflies 

 knows what immense destruction falls 

 to the lot of any species at this stage in 

 its life. Ants and spiders look on them 

 as delicacies made for their delectation, 

 and there is a whole group of tiny 



