PHYSIOLOGY OF LIFE. 77 



taining to the senses, on the other hand, are indistinct, 

 and comparatively unimportant. The multitude of im- 

 movable eyes appear not so much conductors of light, as 

 its ultimate recipient. We are almost tempted to believe 

 that they constitute, rather than subserve, their sensorium. 

 These eye-facets form the sense of light, rather than 

 organs of seeing. Their almost paradoxical number at 

 least, and the singularity of their forms, render it probable 

 that they impel the animal by some modification of its 

 irritability, herein likewise containing a striking analogy 

 to the known influence of light on plants, than as excite- 

 ments of sensibility. The sense that is nearest akin to 

 irritability, and which alone resides in the muscular system, 

 is that of touch, or feeling. This, therefore, is the first 

 sense that emerges. Being confined to absolute contact, 

 it occupies the lowest rank; but for that very reason it is 

 the ground of all the other senses, which act, according 

 to the ratio of their ascent, at still increasing distances, 

 and become more and more ideal, from the tentacles of 

 the polypus, to the human eye; which latter might be de_ 

 fined the outward organ of the identity, or at least of the 

 indifference, of the real and ideal. But as the calcareous 

 residuum of the lowest class approaches to the nature of 

 horn in the snail, so the cumbrous shell of the snail has 

 been transformed into polished and moveable plates of de- 

 fensive armour in the insect. Thus, too, the same power 

 of progressive individuation articulates the tentacula of 

 the polypus and holothuria into antennae ; thereby mani- 

 festing the full emersion and eminency of irritability as a 

 power which acts in, and gives its own character to, that 

 of reproduction. The least observant must have noticed 



