90 COSMIC PHILOSOPHY. [n. n. 



organisms are specialized as tactile. Tlie most perfect 

 orsfans of touch are the vihrissce or whiskers of the cat, 

 which act as long levers in communicating impulses to the 

 nerve-fibres that terminate in clusters about the dermal 

 sacs in which they are inserted. Yet these whiskers are 

 merely specialized forms of just such hairs as those which 

 cover the bodies of most mammals, and which are found 

 evanescent upon the human skin, embedded in minute sacs 

 or re-entrant folds. Now it is a demonstrated fact that the 

 eye and ear are morphologically identical with vihrissce. The 

 bulb of the eye and the auditory chamber are nothing but 

 extremely-metamorphosed hair-sacs, and the same is true of 

 the olfactory chamber. The crystalline lens is a differentiated 

 hair, the aqueous and vitreous humours are liquefied dermal 

 tissue, and the otolites of the ear are " concretions from the 

 contents of an epidermic sac." In view of these astounding 

 disclosures of embryology, we may readily assent to Mr. 

 Spencer's statement that modern science justifies the guess of 

 Demokritos, " that all the senses are modifications of touch." 

 From a single sense, more or less diffused over the surface of 

 the body, and capable of establishing correspondences only 

 with agencies in direct contact with the body, there have 

 arisen, by slow differentiations, such localized senses as sight 

 and hearing, which serve to enlarge the environment and 

 establish correspondences with agencies more and more re- 

 mote. Let us briefly consider the sense of sight, omitting 

 hearing, as well as smell and taste, since our space is too 

 limited to deal with tliem properly. 



In such lowly organized cfeatures as the hydra the ability 

 to distinguish between light and darkness, or between sun- 

 shine and shadow, is possessed in a slight degree by the 

 entire surface of the body. But vision can haidly be said 

 to exist, even in its most rudimentary aspect, until this 

 sensibility is "concentrated in a particular spot. The rudi- 

 mentary eye consisting, as in a planaria, of some pigment 



