18 PRIZE ESSAY: 



to fill the eyes, nose and mouth of all who were in the open air 

 at the time of their visit. W There are numerous species of 

 aphis, forty-nine named species have been recorded by Stephens 

 in his catalogue of British insects. They are found to infest 

 most of our cultivated vegetables. Fortunately they have num- 

 erous enemies, otherwise their wonderful fecundity would enable 

 them to destroy every blade of grass and every green thing in 

 our gardens and fields. 



20. Mr. Curtis states that from one egg, in seven generations, 

 729 millions will be bred ; and if they all lived their allotted time, 

 by autumn everything upon the surface of the earth would be 

 covered by them. Dr. Fitch relates that " on the last day of 

 October, 1854, it being a warm sunny day, after many nights of 

 frost, I observed myriads of winged and apterous lice wandering 

 about upon the trunks, the limbs and the fading leaves of all 

 my apple trees, many of them occupied in laying their eggs. 

 These were scattered along in every crevice of the bark, in many 

 places piled up and filling the cracks, and others were irregularly 

 dropped among the lichens and moss growing upon the bark 

 every unevenness of the surface, or wherever a roughness afforded 

 a support for them, being stocked with as many as could be 

 made to cling to it." 



21. The history of the chinch bug is probably not familiar to 

 the majority of Canadian farmers, as this insect does not yet ap- 

 pear to have crossed the Detroit and St. Clair Rivers ; but while 

 it is to be hoped that many years will elapse before it finds a 

 home in this country, there is reason to fear that sooner or later 

 we may have to deplore, perhaps in a mitigated form, its advent 

 in our midst. As allusion will be made to this destructive and 



(1) See Smee on the potato plant, for numerous instances of the incredible 

 numbers and destructiveness of various species of aphidse. 



