AND THE LOWER ANIMALS. 125 



have attracted the attention of even ordinary ob- 

 servers. 



In a developmental point of view, the histories of 

 man and of the butterfly, although presenting very 

 marked contrasts, yet have some important features 

 in common. In both we find a male and female 

 parent, and offspring which are directly derived from 

 this couple, and which must pass, in reaching their 

 final state, through the same phases as those which 

 characterized their parents. In the vertebrated as in 

 the annulose animal we perceive that the progeny, 

 male and female, resemble the parents, allowing of 

 course for individual differences. In all the groups 

 which have engaged our attention up to the present, 

 the individuality of each being is manifest from the 

 first appearance of the germ, and in the first rudi- 

 ments of the egg, and remains entirely distinct until 

 the. being itself ceases to exist. These facts are well 

 known even to vulgar experience, and till lately 

 scientific and unscientific persons agreed in regarding 

 them as the expression of absolute laws. 



We must now proceed to consider a set of phe- 

 nomena as novel as they are remarkable. Here we 

 meet with animals which, strictly speaking, have 

 neither father nor mother, but simply a single parent, 

 which produces them directly from its own body. 

 We shall meet with sons which never resembled their 

 father, and which produce offspring quite unlike 

 themselves. We shall see a single germ give rise, 

 more or less directly, not to a single individual, but to 

 multitudes of individuals, and even occasionally to 

 distinct generations, which are not related either as 

 to form or structure, or mode of life. We shall thus 



