PIIVSIOLOGY OF INSECTS. 141 



tlien the fifth and sixth approach and unite ; then 

 the third and fourth ; lastly, in the pupa, the 

 seventh and eighth wholly disappear, and eight only 

 are to be found in the perfect butterfly. 



529. The nerves, after leaving the cerebroids, 

 divide, and ramify almost infinitely, being more 

 particularly abundant in the head and tarsi of 

 the legs; they do not appear to penetrate the 

 ossified skin, although they are found close be- 

 neath it, 



530. The nerves are the means by which the 

 circumstances of matter are conveyed to the mind ; 

 and also the means by which the commands of 

 mind are conveyed to matter : in the former 

 capacity they are the organs of the senses. 



531. The senses of insects are, properly speak- 

 ing, seven : love, touch, taste, smell, hearing, 

 sight, and the commanding and governing sense, 

 called volition, mind, thought, or instinct. 



532. Love is that sense which ensures obedience 

 to the great command. Increase and multiply ; its 

 gratification seems the main object of an insect's 

 life, after having arrived at maturity : its seat is in 

 the organs of generation. 



633. Touch is a most invaluable sense to in- 

 sects ; they have two antennae and four feelers 

 attached to the mouth, which appear provided 

 purposely for the exercise of this sense : the 

 tarsi are also employed to ascertain qualities by 

 touch ; but the other parts of the body appear 



