THE WEB OF LIFE 323 



peculiar habit should be considered, not by itself, but in 

 its setting along with the whole constitution and character 

 seems to us still a sound proposition. 



In spite of many suggestions, the puzzle of the peculiar 

 habit remains, and Baldamus, who devoted his whole life 

 to cuckoos, finished up his big monograph with the dis- 

 appointing words : ' All answers to the wider questions 

 of how and why, in my opinion, can be based only on con- 

 jectures : and, however clever many of these may be, for 

 exact science they have scarcely any value at all'. It 

 cannot be said, however, that this is true of the careful 

 study of the behaviour of the cuckoo by Prof. Francis H. 

 Herrick, of Cleveland, which we have utilised' in the 

 foregoing pages. 



ANIMAL SOCIETIES 



Many animals form coherent colonies, by budding or 

 by some form of division, the whole being physically con- 

 tinuous. Every grade occurs between mere aggregates, 

 where the component units are closely juxtaposed but 

 not intimately inter-dependent, as we see in many corals, 

 and subtle integrates where the whole colony may move 

 and behave as one creature, as we see in the free-swimming 

 Portuguese Man-of-War (Physalia) or in the Fire-Flame 

 (Pyrosoma). It is difficult to draw the line logically, but 

 it seems clearer to keep the term colonies for those com- 

 binations where the bond of union is, in part at least, 

 physical. 



Many animals live together in companies, but without 

 there being much or anything in the way of a corporate 



