142 Chapters in Modern Botany CHAP, vn 



the number of cats that destroy the mice." Hence it is 

 quite credible that the presence of a feline animal in large 

 numbers in a district might determine, through the inter- 

 vention first of mice and then of bees, the frequency of 

 certain flowers in that district. 



This may seem a mere matter for naturalists, yet in this 

 connection we touch on practical politics. The British farmer 

 is at this day in many districts sorely exercised by a plague 

 of field-mice and voles with which sheep-pastures are notably 

 swarming. How far is this due to the relentless war waged 

 by the gamekeeper against owls, ferrets, weasels, and all 

 the other mouse-loving creatures, furry or feathered? The 

 Board of Agriculture in the person of Mr. Chaplin, decides 

 not, suggesting climatic causes as the explanation of the 

 pests, if not almost hinting at occult ones, beyond the pene- 

 tration of human intelligence. 1 But on what grounds, i.e. 

 on what actual observation and investigation does this de- 

 liverance rest ? If none, might not the Board of Agriculture 

 as profitably encourage it to be made by the farmers and 

 field-naturalists of each district? The result could not but 

 be instructive ; perhaps unexpected. 2 



- 1 It is of course not inconceivable that we may have in animals 

 as in trees, good " seed - years "; i.e. some internal rhythm larger 

 than the annual one, of unusual fecundity. 



2 As this goes to press, I am glad to learn that the step has 

 been taken of forming a committee to investigate the questions. 



