ii] BIOLOGICAL FOUNDATIONS 55 



surface and volume will increase in almost equal 

 proportion. This method, though it has been used 

 here and there, is not easy of adoption, nor wholly 

 satisfactory when adopted. To obtain a thin film 

 instead of an approximately spherical mass of proto- 

 plasm, the surface-tension must be very materially 

 altered, and this implies a deep and continuous 

 change in the condition of the surface layer as the 

 size of the whole increases. For main result, the 

 method has the suppression or at least the delaying 

 of reproduction. Logically it leads to unlimited 

 growth of the single mass of living matter, so putting 

 all the eggs of the species in one basket ; and even 

 though it is certain that in such a flimsy unco-ordinated 

 film parts would at length be accidentally torn off or 

 simply pull apart from the main body, so reproducing 

 and dispersing the species, yet this reproduction 

 would be long delayed, and the change of structure 

 which involved the delay would have brought few 

 compensating advantages. 



The other method is probably easier of adoption, 

 certainly more beneficial in immediate result. It 

 consists in this, that the disproportioned mass of 

 protoplasm divides into two halves. By this means, 

 though the total volume of living substance is left 

 unaltered, the total surface it exposes is increased by 

 over 50 per cent., and the two halves can thus go 

 on gaily growing until the time comes to repeat the 



