190 [March, 1847. 



American Journal of Science and Agriculture ; conducted by 

 Dr. E. Emmons and A. Osborn, Esq. January and March, 

 1847. From the Editors. 



A letter was read from Miss Morris, dated Germantown, 

 March 5th, 1847, addressed to the Corresponding Secretary, 

 containing the following in relation to the larvae of Cicada 

 septemdecim, presented this evening. 



" I send with this a box containing the larvae of the Cicada 

 which I promised, and believe you will find them satisfactory 

 evidence of the truth of my theory; they were found on the 

 roots of a pear tree, which I had under examination this morning 

 in company with between four and five hundred, which I gathered 

 while the earth was being removed from a trench four feet wide 

 and two deep that was dug around the tree. This experiment 

 was in every way satisfactory, and proved beyond a doubt the 

 correctness of my former observations.* My only surprise was 

 that the tree had lived so long. I then removed the earth from a 

 tree, distant about twelve feet. A quantity of earth and rubbish 

 had been thrown around this tree, some years since, in conse- 

 quence of which, the tree had produced a fresh and vigorous set 

 of roots above those attacked by the Cicada ; passing below these, 

 about two feet, I found the larvae in great numbers, but from the 

 difficulty of getting at them, I believed the remedy would prove 

 worse than the disease ; so covering them up with fresh earth and 

 manure I left the tree to its fate. I then went to a distant part of 

 the garden, and caused the roots of another tree to be exposed, 

 but to my surprise, found but few Cicada, not more than a dozen. 

 This tree had long ceased to bear fruit, and had become withered 

 and dried, several years before any other tree appeared to suffer, 

 but in 1845 it again showed signs of returning life, though no 

 care had been bestowed to restore it ; and in the following year it 

 threw out several fine and vigorous shoots from the branches. 

 On a little further search I found the remedy, as well as the dis- 

 ease, at the root. Mole tracks were to be seen in every direction 

 around the tree and in that portion of the garden. I then ex- 

 amined four other trees, and found that where the mole tracks 



*See No. 6, page 132. 



