in addition, it means mainly the increase of 

 body. But this increase in every separate vital 

 process ceases early or late, although the tendency 

 of self-preservation continues to exist, but the 

 changes lead the organism to final dissociation. 

 The capacity of reproduction, on the 

 contrary, creates new individuals of this species, 

 (p. 73) 



The ability to reproduce is present in two forms. 

 First, it may be considered a result of the 

 necessary influence of one on the other of two 

 materials .... This reproduction is called 

 sexual , even in the case in which male and female 

 sexual organs are present in the same individual. 

 These individuals are called hermaphrodites. The 

 second kind of reproduction is termed asexual 

 reproduction. It is frequently seen in plants and 

 the lower animals. Asexual reproduction in many 

 organisms is found together with sexual reproduction 

 .... This union of both kinds of reproduction 

 can be called, according to Owen, metagenesis, or, 

 according to Van Beneden, digenesis. The expression 

 "alternation of generations". . . must be used only 

 in those conditions when these forms of reproduction 

 are alternated one with the other .... Sexual 

 reproduction can never appear at the beginning of 

 individual development, because the sexual organs 

 must be formed early and secrete their products. 

 The embryo produced by fertilization must always 

 pass through all the stages of development intrinsic 

 to this organism. When asexual reproduction takes 

 place in the mature condition of the female 

 individual, then it is called parthenogenesis. 

 Similar reproduction in the immature condition we 

 suggest calling paedogenesis. The latter may occur 

 in all the different periods of development and may 

 appear in very different forms, and also begins the 

 course of development each time from the beginning, 

 or may only continue it. (pp. 75-76) 



From this it is clear that Baer established an orderly 

 classification of the methods of reproduction, including all 



479 



