80 SOME SOUTH INDIAN INSECTS, ETC. [CHAP. X. 



the less tolerant person, possibly because this contains a smaller 



proportion oi antitoxins, perhaps merely because it is actually 

 red i orpuscles. Be this as it may. we have some evidence 

 to suggest thai one method foi the control of insect-pests of crops 

 may lie in the direction of the breeding and utilizing of pest- 

 resistant stocks ; this is a line of research on the border-line of 

 Entomology and Botany, although the primarj investigation of 

 resistant strains undoubtedly lies within the domain of the 

 Entomologist, and work on these lines will undoubtedly yield 

 valuable results in the future. 



["he destruction oi birds and of other predaceous or parasitic 

 animals which act as natural checks on the increase of insects is a 

 subjeel oi peculiar importance in a country such as India, where so 

 great a proportion of the population is entirely dependent on agri- 

 culture, where mam hi i largely insectivorous as to form 

 constant and very effectual checks on the increase oi insect-pests 

 of crops, and yet where the feeding-habits of these birds and their 

 importance are so little recognised bj the agricultural classes who 

 are most com erned. It must be clearlj understood that no claim is 

 made lure thai all birds, or even all insectivorous birds, are bene- 

 ficial to the agriculturist. The value oi birds, and their relative 

 values, will be discussed more fully in a subsequent chapter and it 

 will suffice to note lure that districts in which the slaughter of 

 insectivorous birds is permitted must expect to repay their debt to 

 nature in the shape of an enhanced and perhaps ruinous toll levied 

 on their crops bj insect-pests which would normally have been 

 kept in check by the birds. 



