PRODUCTIVE BLACKBIRDS. 345 



than one nest at the same time, unless when one 

 had been forsaken. From a careful examination of 

 the ground around the third nest 5 it is inferred 

 that it must have been some winged creature that 

 disturbed the female on the eggs, and destroyed 

 some of them. Was this the male ? " 



In attentively considering this account, it appears 

 probable that had not the third set of eggs been 

 destroyed, the blackbird would have produced no 

 more than that set. And the same remark applies 

 to the fourth. It has been already noticed that 

 birds may be caused to lay a larger number of 

 eggs than they would otherwise do, if by accident 

 their eggs are destroyed or removed. In the 

 instance in question it is, to say the least, impro- 

 bable that another set would have been laid, had 

 not the birds experienced some accidental disturb- 

 ance during the period of incubation. Colonel 

 Montagu considered that few birds, if any, would 

 produce a second brood in the same season if un- 

 molested. He adds, " We have never been able 

 with any certainty to discover either in the red- 

 breast or hedge-sparrow, who are the earliest 

 breeders, the production of a second brood after 

 the first has been brought to maturity. Their 



