12 ANIMAL INDIVIDUALITY [CH. 



and in non-conscious organisms at least, difference of 

 function always implies difference of structure, so that 

 the more independence the more individuality an 

 individual is to possess depends very closely on the 

 amount of heterogeneity of its parts. Look for 

 instance at such an individual as a colony of Termites 

 ("white ants") (cf. p. 142), its defence delegated to 

 one caste, its nutrition to another, its reproduction 

 to another ; the various castes are specially adapted 

 in their structure for their various functions. It is 

 obvious at once that the queen with her vast swollen 

 abdomen full of eggs is a much more effective repro- 

 ducer than if she had retained any of the structure 

 and mobility necessary to defend or look after her- 

 self. The soldiers again could not have been such 

 powerful defenders of the colony if they were to have 

 kept any of the delicacy of mandible required by the 

 workers, the craftsmen. 



Another illustration : the accurate grasping powers 

 of the human hand are only rendered possible by its 

 consisting of a number of distinct but co-ordinated 

 parts. The action of grasping is an undivided and a 

 single act, but is only possible because the organ of 

 grasping consists of separate and different parts. 

 The pseudopod of an Amoeba, to take the opposite 

 extreme, has no differentiation of parts: hence the 

 functions it can perform are few and imprecise. 



In both these cases, the dependence of efficient 



