INTERNAL ANATOMY OF INSECTS. 23 



before described a , shows this more evidently : but one 

 of the most remarkable stories to our purpose upon re- 

 cord, is that of M. Pelisson, who, when he was confined 

 in the Bastile, tamed a spider, and taught it to come for 

 food at the sound of an instrument. A manufacturer 

 also in Paris, fed 800 spiders in an apartment, which 

 became so tame that whenever he entered it, which he 

 usually did bringing a dish filled with flies but not al- 

 ways, they immediately came down to him to receive 

 their food b . 



All these circumstances having their due consideration 

 and weight, it seems, I think, most probable, that as in- 

 sects have their communication with the external world 

 by means of certain organs in connexion with their ner- 

 vous system, and appear to have some degree of intel- 

 lect, memory, and free will, all of which in the higher 

 animals are functions of a cerebral system, and at the 

 same time in other respects manifest those which are 

 peculiar to the sympathetic system, it is most probable, 

 I say, as was above hinted, that in their system both are 

 united. 



I must bespeak your attention to a circumstance con- 

 nected with the subject of this letter, which merits parti- 

 cular consideration: I mean the gradual change that 

 takes place in the nervous system when insects undergo 

 their metamorphoses ; so that, except in the Orthoptera^ 

 Hemiptera, and Neuroptera Orders, in which no change 

 is undergone, the number of ganglions of the spinal chord 

 is less in the imago than in the larva. There seems an 

 exception indeed to this rule in the case of the rhinoceros- 



a VOL. II. p. 204. * N. Diet. d'Hist. Nat. ii. 279. 



