36 



PROCEEDINGS OF THE 



xii. The exclusion of house- flies : tlie utilization of natural enemies. 



" I suogest that wooden frames be covered with metal 

 wauze such as is used for sieves, and hinged on outside of 

 doors and v^^indows, otherwise, with free access to your 



houses, what can be safe from the Fly ? How 



to accomplish this [the extermination of the Fly], and also 

 annihilate the swarms of Ticks, Fleas, Gnats, Bed-Bugs and 

 so forth, is indeed a question. Of course cleanliness will 

 affect something towards the desired end ; but, perhaps, 

 more than this may be called into play : maybe other 

 creatures can be bred that may abate the numbers of these 

 vermin, just as the Mungoos is used by the Hindu to destroy 

 the Cobra-di-Capello, as the Ferret is set upon the Rat in 

 England and the Ladybird is said to be employed in the 

 South of Europe to exterminate the larvaj of various insects 



that prey on the poor peasant's scanty crops " 



(pp. 32-33.) 



The author brings his second lecture to a close in a paragraph 

 which obliterated 40 years and made me a boy again, reading 

 Herbert Spencer's ' Principles of Biolog}^' for the first time. 



" All this ", he is alluding to his germ theory and its 

 possibilities, " I believe will be proven to be fact, and in 

 its darker aspect we are yerj naturally brought to see no 

 hand of God. For what just, compassionate and merciful 

 Father Diety would let loose a host of death dealing, 

 raveiious Wolves in miniature, upon ignorant, frail, sup- 

 plicating creatures of his kindly creation — his own, fore 

 known, fore-destined, children ? " (pp. 35-36.) 



Similarl}', Herbert Spencer, after describing the adaptations by 

 which a number of parasites are enabled to wage successful \\r\.v 

 upon mankind, continues : — 



" What shall we say to this arrangement? Shall we say 

 that man, ' the head and crown of things/ was provided as a 

 habitat for these parasites ? Or shall we say that these 

 degraded creatures, incapable of thought or enjoyment, were 

 created that they might cause unhap})iness to man ? One or 

 other of these alternatives must be chosen by those who 

 contend that every kind of organism was separately devised 

 by the Creator." (' Principles of Biology,' London, 1864, 

 vol. i. pp. 343-4.) 



