2 



INHERITANCE. 



Chap. XII. 



identically the same. All wild animals recognise each other, 

 which shows that there is some difference between them ; and when 

 the eye is well practised, the shepherd knows each sheep, and 

 man can distinguish a fellow-man out of millions on millions of 

 other men. Some authors have gone so far as to maintain that 

 the production of slight differences is as much a necessary func- 



tion of the powers of generation, as the production of offspring 

 like their parents. This view, as we shall see in a future 

 chapter, is not theoretically probable, though practically it holds 

 good. 



The saying 



that 



like begets like" has in fact arisen 



from the perfect confidence felt by breeders, that a superior or 

 inferior animal will generally reproduce its kind ; but this very 

 superiority or inferiority shows that the individual in question 

 has departed slightly from its type. 



The whole subject of inheritance is wonderful. When a new 

 character arises, wmatever its nature may be, it generally tends 

 to be inherited, at least in a temporary and sometimes in a most 

 persistent manner. What can be more wonderful than that 

 some trifling peculiarity, not primordially attached to the species, 



should be transmitted through the male or female sexual cells, 



which are so minute as not to be visible to the naked eye, 

 and afterwards through the incessant changes of a long course 

 of development, undergone either in the womb or in the egg, 

 and ultimately appear in the offspring when mature, or even 

 when quite old, as in the case of certain diseases ? Or again, 

 what can be more wonderful than the well-ascertained fact 

 that the minute ovule of a good milking cow will produce a 

 male, from whom a cell, in union with an ovule, will produce 

 a female, and she, when mature, will have large mammary 

 ;lands, yielding an abundant supply of milk, and even milk 



8 



of a particular quality ? Nevertheless, the real subject of sur- 

 prise is, as Sir H. Holland has well remarked, 1 not that a 

 character should be inherited, but that any should ever fail 

 to be inherited. In a future chapter, devoted to an hypothesis 

 which I have termed pangenesis, an attempt will be made to 

 show the means bv which characters of all kinds are trans- 

 mitted from generation to generation. 



i 



' Medical Notes and Keflections,' 3rd edit., 1855, p. 267. 



