286 THE CULTIVATION OF THE 



any way. The trees in his orchard, receiving every care 

 of cultivation and fertilizing, sadden his heart in yield- 

 ing to the destructive influences of that disease, and so 

 he argues that they are receiving the wrong treatment, 

 and he will leave them to nature, as he does the tree in 

 his yard, and they will, necessarily, thrive as it does. 

 He is wrong, he is reasoning from false premises. 

 Isolated pear trees, as a rule, never blight, they only 

 blight when crowded in orchard culture. Here the 

 bacteria increase and multiply to the point where they 

 become a disease, just as they do under the same cir- 

 cumstances with mankind, and this is the reason his 

 favorite tree in the yard flourishes, while his orchard- 

 trees wither and die. 



THE SLUG. 



Next to blight, the slug is, probably, the most 

 serious enemy of the pear on the peninsula, now active. 

 Here we call it the slug worm, from its snail-like, slimy 

 character. In England they call it the slimy grub of 

 the pear tree. Scientists generally speak of it as Harris 

 does, as the Selandria {Blenno Campd) Cerasi. Blenno 

 Campa signifies slimy caterpillar. It is a species of saw 

 flly, and the above name is the name of the fly. Another 

 name is, or rather a name for the slug is, Erio campa 

 adumbrata. 



According to Harris, the slug fly is of a glossy black 

 color, except the first two pairs of legs, which are dirty 



