18 COLIN CLOUT'S CALENDAR. 



by one. Thus, if we may believe so plausible a theory, 

 by a sort of unconscious hereditary teaching the memory 

 of the lost land-connections has been handed down from 

 one generation to another since pre-glacial times. Were 

 Corsica and Sardinia now to sink slowly beneath the 

 waves, it is not difficult to conceive that the swallows 

 might still gather yearly upon the hills at Mentone, and 

 fly southward across the blank space to Tunis under 

 guidance of their most experienced elders. 



