24 TRANSACTIONS OF THE SOCIETY. 



The desire which has been manifested in the community to possess a 

 knowledge of this insect, the manner in which he operates, and a means 

 of destroying him, must be my apology for thus far prolonging these 

 remarks. 



Warty or Black Excrescence. 



A communication from William Prince & Co., some few weeks since, to 

 the editor of the New England Farmer, in which a list of the kinds of plum 

 is made out, which, they say, are not subject to the fungus or warty ex- 

 crescences, has induced me to slate my opinion concerning the nature of 

 that disease. 



I do not remember to have seen that disease spoken of, except in con- 

 nection with the belief that it is caused by an insect ; and I believed it to 

 be so produced, until observation proved to me that it was attributed to the 

 wrong cause. The reason any one would offer as proof that the disease 

 was caused by the Curculio, is, that its larvsc are sometimes found in this 

 juicy fungus. 



There is one analogous reason for attributing this fungus to the Curculio, 

 or some insect ; that is, the production of galls upon the oak by the punc- 

 ture of an insect, and the depositing his egg in the puncture. But how 

 uniform, in form and size, are these galls, compared with these excrescen- 

 ces, which are very irregular in form and size ! 



So far as I have been able to observe; by dissecting these fungi, they 

 appear to arise in that part or texture called the alburnum. 



I have thought that the proximate cause might be, an obstruction in the 

 vessels of that texture, by reason of the unhealthiness of the sap. The 

 vessels burst, and the sap is poured out under the bark. Now, the sap is 

 as full of the life of the tree, as blood is full of the life of an animal. 



This extravasated sap will immediately become organized, or partially 

 so, and, rapidly increasing, burst through the outer bark and make its ap- 

 pearance. 



This fungus is not confined to the young wood, but is produced upon 

 limbs of large size, the outer bark of which the Curculio would not be 

 able to puncture. 



It makes its appearance from June up to August. These fungi come 

 in all forms ; sometimes in a single spot, and then again extend along the 

 limb for several inches, always with an irregular granulated surface. This 

 want of uniformity in form, size and location, is evidence that it is not 

 caused by an insect. After being cut from the large limbs, these fungi 

 will often sprout out again between the wood and the bark where the 

 wound is made, and require a second operation. 



Now, this would not be the case if caused by an insect. This disease 

 may often be noticed under the bark before it bursts, upon large limbs where 



