55 THE PSYCHIC LIFE 



therefrom are often numerous, and it is not until the 

 plasma has finished dividing that the maternal cuticle 

 is destroyed and that the segments separate to live 

 abroad in a detached state. Up to that time they re- 

 main bound together. 



It is thus seen that the existence of this minute 

 colony is a transient phenomenon, which lasts only 

 during the time necessary for the division of the ma- 

 ternal body. These phenomena have been noticed 

 among many of the Flagellates. What appears surpris- 

 ing is, that the maternal cellule, although continuing to 

 divide beneath the envelope, keeps on moving about 

 in the water by means of its own flagellum as if still 

 constituting only a single animal. The reason of this 

 is that one of the segments into which the plasm is 

 divided and which is situated in the anterior part of 

 the mother-cellule, remains connected with the flagel- 

 lum and takes charge of its movements. This seg- 

 ment (like an individual distinct in itself) alone guides 

 the' bark that carries its sisters. And so, although 

 this diminutive colony is as a rule but short-lived, a 

 division of labor has been effected among its mem- 

 bers; the anterior segment is alone entrusted with the 

 office of locomotion. 



The colony has a duration less ephemeral in the 

 case of the Gonium pectorale, a Volvocine known in 

 our fresh waters. It is formed by the aggregation of 

 sixteen individuals which remain detached but ad- 

 here laterally to one another. The colony is de- 

 veloped in one way only: it is in the form of a minute 

 rectangular plate of a beautiful green color. In the 

 case of the Pandorina, the colony assumes the form of 

 a minute sphere; it is composed of sixteen, or as many 

 as thirty-two individuals, joined together beneath a 



