Anaholism and Specialisation. 205 



process of evolution. Throughout all these changes, it is 

 evident that a permanence in the change was the most 

 beneficial to the life of the plant. Unlike animals, which 

 expend much energy in order to live, and which are therefore 

 loth to give up the material so dearly attained, plants, in 

 choosing this line of specialisation, and foregoing the produc- 

 tion of much kinetic energy, have often to be lavish in 

 expenditure of material to meet the changes imposed upon 

 them. To form material cheaply, or with the least expendi- 

 ture of energy, must therefore dominate their specialisation. 



To return to the primitive forms. Those whose tendencies 

 were to the formation of more unstable products of anabolism 

 would require a greater nutrition than their more stable 

 sisters, and could not afford to wait until it came to them. 

 Constant locomotion alone would find for them the most 

 favourable localities for obtaining a sufficient supply of food, 

 and constant movement of some kind would alone allow of 

 their getting rid of their gradually increasing waste products. 

 The power of ingesting already living material into their 

 protoplasm would constitute a great advance in quickly 

 gaining large amounts of nutritious food. At a time when 

 the bulk of living forms still persisted in dividing and 

 separating at the limit of growth, any form which arose with 

 a tendency to a hollow spherical shape, through the com- 

 ponent individuals adhering to one another after division, 

 would allow of the passive locomotion of those whose hunger 

 was for the time appeased, by the continued movements of 

 the rest of the colony, while all would be equal in their 

 relation to the outside world. A tendency for the sphere to 

 become bag-shaped through the invagination of a part of its 

 surface, though offering different advantages to different 

 members of the colony, would be highly efficient in acting as 

 a tow-net, by capturing the small organisms around it on a 

 more extensive scale. The supply of food thus attained 

 might in time become so great as to gorge the colony to 

 repletion, and to cause it to return to a more sedentary form 

 of life, with a tendency to fix itself to the bottom. From this 

 point the building up of the coelenterate type of life would 

 begin through division of labour in the different components 



