48 INTELLIGENCE ANL> INSTINCT. 



Some of them collect only honey and wax ; while others 

 are charged with the care and education of the young ; and 

 still others, are the natural chiefs of the colony. 



144. Finally, there are certain animals so guided by their 

 instinct as to live like pirates, on the avails of others' 

 labor. The Lestris or Jager will not take the trouble to 

 catch fish for itself, but pursues the gulls, until, worn out 

 by the pursuit, they eject their prey from their crop. Some 

 ants make war upon others less powerful, take their young 

 away to their nests, and oblige them to labor in slavery. 



145. There is a striking relation between the volume of 

 the brain, and the degree of intelligence which an animal 

 may attain. The brain of man is the most voluminous 

 of all, and among other animals there is every grada- 

 tion in this respect. In general, an animal is the more 

 intelligent, in proportion as its brain bears a greater re- 

 semblance to that of man. 



146. The connection between instinct and the nervous 

 system does not present so intimate a correspondence as 

 exists between the intellect and the brain. Animals which 

 have a most striking development of instinct, as the ants and 

 bees, belong to a division of the Animal Kingdom where the 

 nervous system is much less developed than that of the ver- 

 tebrates, since they have only ganglions, without a proper 

 brain. There is even a certain antagonism between instinct 

 and intelligence, so that instinct loses its force and peculiar 

 character, whenever intelligence becomes developed. 



147. In man, instinct plays but a secondary part, but he 

 is not entirely devoid of it. Some of his actions are entirely 

 prompted by instinct, as for instance, the attempts of the in- 

 fant to nurse. This fact again, that instinctive actions pre- 

 ponderate in infancy, when intelligence is but slightly de- 

 veloped, goes to confirm the two last propositions. 





