1869. 



XEW ENGLAm) far:\ier. 



479 



or when they fall in the autumn ? I have set out 

 quite a nuniher this s-eason, and I have yet to learn 

 about the poisonous properties of tlieir leaves, if 

 in any considerable degree tht-y are so. d. w. n. 

 Sterling, Mass., Aug., 1869. 



Rem AUKS. — The leaves of peach trees contain a 

 certain amount of prussic acid, and are undoubt- 

 edly poisonous. If eaten in large quantities they 

 would be likely to kill cattle. We should prefer 

 not to risk them where they could tind abundance 

 of leaves, either in a green or wilted state. Even 

 if there were plenty of grass for the stock, they 

 might prefer the peach leaves. Cases of death 

 have occurred in children by eating the meat of 

 the peach stones. The bitter taste in the leaves 

 and stone, is occasioned by the presence of prussic 

 acid. 



BLACK-KNOT ON CHERRY TREES. 



Thirteen years ago I took up five cherry trees, 

 covered with black-knot, like specimen enclosed, 

 brought them on my baikfour miles and set them 

 out m the girden. They have grown well and are 

 now handsome trees. They bear abundantly every 

 year, atlbrd a delightful shade and are truly an 

 ornament to the garden. But in all directions in 

 the neighborhood, the cherry trees are being spoiled 

 by ttie black knot. When I ask my neighbors 

 why they allow their trees to be thiis distit;ured 

 and spoiled, the invariable answer is, "I can't help 

 it." My own trees have been preserved simply by 

 removing the excrescences. My father carefully 

 watches them, and as soon as a branch is found to 

 be atiecteil it is removed, if not too large. If the 

 limb IS too large, ihe "knot" is shaved off clean. 

 This is all that has been done. On examinirig 

 these black bunches we invariably find from one 

 to half a dozen grubs or worms, varying in size 

 from a microscopic mite to worms haif an inch in 

 length- Now as I am not much of a worm-arian, 

 will you plea-^e to give me through the Farmer 

 some ii.fiirmation as to the character and habits of 

 this desiructive insect ? I suppose they remain in 

 the excrescence until the first stage of ttieir exist- 

 ence is prrfjrmed, when they assume a different 

 shage, aeposit their eggs on other branches and 

 thus perpetuate the -^pecit s. Zen. 



iSpringvale, Me., J-uly 29, 1869. 



Remarks. — On cutting into the black mass on 

 the twig you sent, we found two worms about one- 

 fourth of an inch in length, with a reddish head, 

 flesh-colored, bare bodies. But according to the 

 books, we have yet to prove that tiese warts are 

 caused by insects. Dr. Walsh, of the American 

 Entomologist believes they are caused by a minute 

 fungus, like rust on wheat, mildew on grapes, &c. 

 He says that they ripen their seeds, or "spores" as 

 botanists term it, the latter part of July, which 

 then float in the air like thistle seeds, and plant 

 themselves on the bark of the limbs of trees. 

 Prof. Han is, in his book on Insects Injurious to 

 Vegetation, is undecided as to the origin of the 

 black-knot. He gives the opinions of naturalists 

 both for and against the theory of the insect origin 

 of the disease. He says, "but whether caused by 

 vitiated sap, as Dr. Burnet supposed, or by the ir- 

 ritating punctures of insects, as believed by Prof. 

 Peck, which is the prevailing opinion, or whatever 

 be their origin and seat, they form an appropriate 



bed for the growth of numerous little parasitical 

 plants or fungi, to which botanists give the name 

 of Sphmria moibosa. These plants are the minute 

 black granules that cover the surface "f the wart, 

 and give to it its black color. When fully matured, 

 they are filled with a gelatinous fluid, and have a 

 little pit or depression on their summit. They 

 come to their growth, discharge their volatile seed, 

 and die in the course of a single summer; and 

 with them peri>hes the tumor whence they sprung. 

 It is worthy of remark that they are sure to ap- 

 pear on these warts in due time, and thai they are 

 never found on any other parr, of the tree. 



"Insects are often found in the warts of the plum 

 tree, as well as in those of the cherry tree. The 

 larva) of a minute Cynips, or gall fly, is said to in- 

 habit them, but have never falkn under my ob- 

 servation. The naked caterpillars of a minute 

 moth are very common in the warts of the plum 

 tree, in which also are sometimes found other in- 

 sects, among them little grubs from which genu- 

 ine plum-weevils have been raised." 



Dr. Walsh believes that the fungus that causes 

 the warts on plum trees is of a different species 

 from that whi h causes the warts on cherry trees, 

 and that the plum-knot is not propagated by the 

 cherry-knot, nor vice versa. 



habits of the purple martin. 



Can some of the readers of your worthy paper 

 give me some information in regard to the man- 

 ners and habits of the bird known as the Large 

 Black Martin. They build in the houses of some 

 of my neighbors erected tor their use, to the num- 

 ber of twenty or thirty in a house, while I have 

 one larger .ind superior to theirs that is always va- 

 cant. Can some reader inform me the cau^e ? 



June 12, 1869. A Subscriber. 



Remarks. — The above inquiry was submitted 

 toE. A. Samuels, Esq., author of "Birds of New 

 England and Adjacent States," who has very 

 kindly furnished the following suggestions, which 

 we take much pleasure in publishing not only as a 

 reply to the question of our correspondent, but as 

 containing hints that will undoubtedly be valua- 

 ble to other readers of the Farmer who may like 

 to cultivate the acquaintance of these social birds. 

 Mr. Samuels says : — 



"The peculiarity of the martin in avoiding certain 

 houses and localities has been repeatedly noticed, 

 but never satisfactorily accounted for. We have 

 known of numbers of instances of the birds flack- 

 ing to a martin house and crowding and fighting 

 for possession of the apartments in it, while 

 another house apparently as attractive, convenient 

 and favorably located was avoided persistently. 



Several points are to be taken into consideration 

 in the erection of a martin house. It should have 

 large rooms with entrances on different sides. We 

 have known of a box being avcided when its en- 

 trances faced a certain point of the compass, and 

 when taken down and turned in a different direc- 

 tion, it was at once inhabited by several families. 



Especial care should be taken to secure protec- 



