594 THE REPRODUCTIVE FUNCTIONS. 



are formed ; and they are generally divided into 

 compartments; the whole being enclosed in a 

 membranous covering, bearing a great resem- 

 blance to the seed-capsules of plants. 



The propagation of living beings by means of 

 ova or seeds, is a process of a totally different 

 class from their multiplication by mere slips or 

 buds ; and the products of the former retain 

 less of the peculiar characters of the individual 

 from which they spring, than those of the latter. 

 This is remarkably exemplified in the case of 

 orchard trees, such as apples and pears ; for all 

 the trees which derive their origin from shoots, or 

 grafts from the same individual, partake of the 

 same properties, and produce a fruit of nearly 

 the same flavour and qualities ; whereas trees of 

 the same species, which grow from seed, have 

 the characters of distinct individuals, and losing 

 all the peculiarities that may have distinguished 

 the parent, revert to the original type of the 

 species to which they belong. Thus from the 

 seeds of the golden pippin, or nonpareil, arise 

 trees bearing the common crab apple, which is 

 the natural fruit of the species. By continued 

 graftings, after a long period, the vitality of the 

 particular variety is gradually exhausted, and 

 the grafts no longer bear the same fruit. This 

 has already happened with regard to the two 

 varieties of apples just mentioned. For these 

 curious facts, and the theory which explains 



