138 THE CANADIAN HORTICULTURIST. 



happened to get a book of " God and His Providence in His Insects," 

 describing how wonderfully God has given to every insect the means 

 of progeneration, even with the odds of man's destructive inventions 

 against them, and also other natural enemies, such as birds and insects. 

 Unfortunately the name of the writer has passed out of my memory. 

 I know it is a Belgian writer. He explains many facts in ways which 

 seem plausible, among others this of the black knot. I had already 

 remarked this, and as well as the author came to the conclusion that 

 the cause of it is an insect which instils through a sting an acid into 

 the bark of the tree. This causes the sap to become poisoned, and 

 makes it swell and become of a spongious nature, thus enabling the 

 egg which is laid into the cavity (made by the proboscis of the insect) 

 to hatch out by the heat of the sun. Then it grows and works through 

 the soft spongious matter until it Ijecomes alive, remaining then until 

 it becomes a reddish worm about half an inch long. It ordinarly 

 drops out towards the end of July, digs into the ground and turns into 

 a chrysalis ; some come out and some remain, like the potato slugs. 

 The birds kill a good many off. It prefers the plum tree which 

 exudes the gummy matter, thus the cherry tree as well. 



You will not find a worm in every outgrowth, because not every 

 egg happens to hatch out, or to remain in the cavity the insect makes. 

 It begins its devastating work early in the spring, many remaini'ug 

 and hiding in the crevices of trees or elsewhere. If the spongious 

 matter be cut off the worm dies, and though we do not burn it, the 

 insects cannot live any longer. As long as tliere be any of the acid 

 left in the bark it will run up, but if well pared off, the bark will 

 partly grow over it. 



There is besides a plum borer, having the same shape as the apple 

 borer, big headed, which runs under the bark into the tree and causes 

 it to die. We have all these pests to contend with. Until an effort 

 be made hj disinterested and generous persons, single-handed work 

 will not do, for in a short time cherry and plum trees will have to go. 

 In this neighborhood none care to cut down tlieir trees, or to pare off 

 the evil, so that there is an ample chance for them to multiply. They 

 will afterwards attack the pear and peach trees, and even apple trees. 

 "With all our laws it remains .where it is, as the thistle law, without 

 sanction. The fire will not destroy all these enemies if man has no 

 \M11 to work to combat them, and he will have to do so to enjoy the 



