70 THE PSYCHIC LIFE 



having the shape of minute jugs, and also detached 

 individuals called Microgonidia, which are formed by 

 repeated divisions upon the colonial tree. 



These Microgonidia have exactly the same mode 

 of locomotion as the spermatozoids. Engelmann * has 

 followed their movements. He has seen them swim- 

 ming about turning upon their axis for five or six 

 minutes; then, having come into the vicinity of a Vor- 

 ticel, they abruptly change their manner of movement, 

 capering about the latter like a butterfly flitting about 

 a flower, touching it, retreating, and then approaching 

 it again and apparently feeling of it; at last, after 

 having visited the others near by, they return to the 

 first one and fasten themselves upon, its surface. The 

 coition is not effected without a certain show of re- 

 sistance on the part of the Vorticel. It hastily con- 

 tracts the peduncle to which it is attached, at every 

 touch of the Microgonidium, while the latter in order 

 to prevent itself from being thrown back by these 

 rapid shocks and in order to be always close to the 

 individual with which it wishes to unite, fastens itself 

 by an extremely fine -filament to the style of the Vor- 

 ticel; thus attached and drawn along with the move- 

 ments of the latter, it finally succeeds in effecting a 

 junction with it and in penetrating into its body.f 



It is now time to describe the material phenomena 

 that take place in the interior of the two Infusoria, and 

 which constitute the material act of fecundation. The 

 psychical manifestations which we have just noted 

 and which so strikingly resemble the manifestations 

 accompanying the copulative act in higher animals, 

 are of themselves sufficient evidence that this conju- 

 gation is a sexual union. 



* Arch, de Zoolog. experimental, Vol. V, 1876. 

 \ Journal de Micrographie, 1882, p. 241. 



