n. 



THE STRUGGLE FOR EXISTENCE IN THE GENUS 

 BASILARCHIA 



The power of reproduction conceded, the univer- 

 sal instinct for self-preservation is the fundamental 

 and controlling principle by which the perpetuation 

 of any kind of animal is successfully reached. The 

 uncontrollable maternal instinct of self-sacrifice 

 existing in some creatures alone overmasters it, and 

 this exists only in the higher animals, which, com- 

 pared 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 butterflies, nor is in any way 

 likely to be found, so that " self-preservation " and 

 " j)erpetuation 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 con- 

 vertible terms. 



This struggle is the perpetual inheritance of the 

 individual. The individual inherits alike its struc- 



