300 Wisconsin State noRTicuLTURAL Society. 



galls made by any known insect. Secondly, although insects or 

 remains of insects are generally found in old knots, in most cases 

 no insects at all are found in them when young. Thirdly, the 

 insects that have been found by entomologists in the knots are 

 not all of one species, but of several different species which are 

 also found on trees that are never affected by the knot. On 

 the other hand, we never have the black knot without the 

 Sphceria morhosa, as was admitted by Harris, and the mycelium 

 of that fungus is found in the slightly swollen stem long before 

 anything which could be called a knot has made its appearance. 

 Furthermore, the Splurna morhosa is not known to occur any- 

 where except in connection with the knots." 



With a knowledge of the nature of this contagious disease, the 

 remedy at once suggests itself, namely, to cut off the knots, 

 together with the swollen portions of the branches, whenever and 

 "wherever they are found. In autumn, as soon as the leaves fall, 

 the knots can be most easily seen, and all branches bearing them 

 should be cut off and burned at once. Though the sexual spores 

 do not form until late in winter, it was carefully observed that 

 were the knots left undestroyed they would ripen after the branch 

 was cut from the tree. The choke cherry, bird cherry, and wild 

 plum furnish means for rapid propagation of the knot, and they 

 should be gladly sacrificed for the good of their more worthy allies. 

 Knowing the cause, nature, and means of propagation of the 

 black knot, it is for the fruit growers to profit by their instruction 

 and use their best endeavors to destroy this pest. It is now pecul- 

 iar to America, and any means ot introducing it into other 

 countries should be carefully avoided. 



In concluding this general and very incomplete account of 

 fungi, perhaps it will not be more than justice to give a notice of 

 some of these parasitic plants which prey upon living animals. 



Who has not seen house-flies in autumn, crawling slowly upon 

 the wall with their bodies covered with a white powder, making 

 them appear as if they had paid a visit to the flour barrel ; or, 

 later still, found them fastened in death to the wall or window 

 pane? The struggle between the animal and vegetable has been 

 won by the latter, which in due time must also perish when the 



