216 ANIMAL FORCES. [ii. 



as transmit internal impressions, then the nerve-actions produced 

 by the two kinds of impressions are the same, and also identical 

 with the direct sentient actions of the external sensations (188). 

 If, however, other nerves, or nerve fibrils, be the channel of the 

 reflexion, other nerve-actions are excited, which accord with 

 the sentient actions of the external sensation produced by th( 

 impression so reflected (97, 124; compare also 435, 436). 



400. In so far as an external impression can excite a non-con- 

 ceptional internal impression, it may also induce all such nerve- 

 actions as can be produced by the latter. Now, these are in 

 fact the same as sentient actions (363) . Consequently, an external 

 impression although unfelt, can induce the same movements 

 which, when felt, it induced as sentient actions (364, i). In the 

 animals destitute of brain, as sea-anemones, tape-worms, &c., 

 and in microscopic animals, polypes, &c., external impressions, 

 although unfelt, can be the incitants of the machines, whereby 

 they are incited to all those movements which arise as sentient 

 actions from sensation, when the impressions are felt by these 

 or other animals (366). If, therefore, brainless animals like 

 those alluded to, are so formed by nature, that all their external 

 impressions are reflected, and changed into non-conceptional 

 internal impressions, in the plexuses, ganglia, and points of 

 division of the nerves, and which move their Hmbs just as they 

 would have been moved by sentient actions, it ought not to 

 be matter for surprise, that such animals although without 

 thought or sensation, appear to act as designedly, spontaneously, 

 thoughtfully, and volitionally, as animals really endowed with 

 mind. 



401. A non-conceptional impression can develop obvious 

 animal movements in the purely sensitive nerves (377). Still 

 more can it put muscles into action by means of the motor 

 nerves (360). These muscular movements in the healthy con- 

 dition of the individual (225), are often felt, and consequently 

 cause an external impression on the nerves of the muscles (35), 

 and which, even if not felt, can excite the same movements 

 as if they were. In this way non-conceptional impressions 

 can produce external impressions, which, although not felt, 

 still imitate in the mechanical machines the sentient action of 

 their external sensation. Thus, if the spinal cord of a headless 

 frog be irritated with a needle, the internal impression thus 



