THE EMBRYOLOGY OP THE SOUL. 139 



— In the act of procreation a portion is detached from 

 both the (immaterial) souls of the parents; the 

 maternal contribution passes in the ovum, the 

 paternal in the spermatozoa ; when these two 

 germinal cells coalesce, the two psychic fragments 

 that accompany them also combine to form a new 

 (immaterial) soul. 



Although the poetic fancies we have mentioned as 

 to the origin of the individual human soul are still 

 widely accepted, their purely mythological character 

 is now firmly established. The deeply interesting 

 and remarkable research which has been made in 

 the course of the last twenty-five years into the more 

 minute processes of the impregnation and germination 

 of the ovum has made it clear that these mysterious 

 phenomena belong entirely to the province of cellular 

 physiology (cf. p. 47). Both the female element, 

 the ovum, and the male fertilizing body, the sperma 

 or spermatozoa, are simple cells. These living cells 

 possess a certain sum of physiological properties to 

 which we give the title of the " cell- soul," just as we 

 do in the permanently unicellular protist (see p. 48). 

 Both germinal cells have the faculty of movement 

 and sensation. The young ovum, or egg-cell, moves 

 after the manner of an amoeba ; the minute sperma- 

 tozoa, of which there are millions in every drop of 

 the seminal fluid, are ciliated cells, and swim about 

 as freely in the sperm, by means of their lashes or 

 cilia, as the ordinary ciliated infusoria (the flagellata). 

 When the two cells meet as a result of copulation, 

 or when they are brought into contact through arti- 

 ficial fertilization (in the fishes, for instance), they 

 attract each other and become firmly attached. The 

 main cause of this cellular attraction is a chemical 



