EFFECTS OF COLD UPON INSECTS. 99 



migratory birds seem to have been aware of this abun- 

 dance of insects by their appearing earlier than usual. 

 We saw a pair of nightingales at Greenhithe on the 

 21st of March, and a number of swallows the same 

 week at Lee, which is two or three weeks before 

 their average time.* 



* J. R. 



