3 6 Heredity. 



scale, from the lowest organisms, possessed of no other sense 

 than that of an obtuse, passive touch, up to those most highly 

 sensitive, we see at once that each animal derives a certain 

 number, and a certain kind of senses from its parents. Heredity 

 governs both the quantity and quality of the perceptive faculties, 

 so far as those general characters are concerned which we call 

 specific. 



Heredity also governs all that concerns race or variety. Thus, 

 the dog inherits not only a very acute scent, but also the variety of 

 scent which adapts him for hunting a definite kind of game. In 

 the negro the acuteness of this same sense characterizes that 

 variety of the human species. 



Doubt, therefore, can arise only with regard to individual 

 differences, and thus our original question is transformed into this: 

 Is the transmission of secondary and individual characters governed 

 by the same heredity which governs the transmission of the percep- 

 tive faculties, in their essential and fundamental features? The 

 answer can only be given by facts ; we shall see that heredity is 

 usually the rule, even with what is individual, anomalous, and 

 capricious. 



We take, then, in order, the five senses as usually accepted. 

 There is now a general agreement to recognize, under the name 

 of vital sense, organic sense, or internal sense, a mode of sensa- 

 tion, without a special organ, diffused over the entire body, and 

 which is, as it were, an internal Touch, whereby we are sensible of 

 what takes place within us. But as this sense is entirely personal, 

 making us acquainted with our own body, and not with the 

 external world, and as it very nearly concerns our pleasures, our 

 pains, our instincts, our passions, we will treat of it in another 

 place, when discussing the modes by which our feelings act, and 

 the heredity of these modes. 



I. OF TOUCH. 



Touch is the universal, primary sense, possessed by every 

 sentient animal. All the other senses are but a modification of 

 touch, said one of the ancients. Mr. Herbert Spencer has shown 

 how, by evolution and specialization, the other senses sight, hear- 

 ing, smell, taste could have sprung from touch ; and how touch 



