114 Corydalis formosa and Corydalis canadensis. 







for the present season, barren. An Isabella that bore three hundred 

 bunches the last year, is now destitute of fruit. 5 ' 



J had recollected that in the preceding season (1830) the vine leaves 

 were infested by a " small chesnut colored smooth worm ;" and in 

 that year (1831) it again appeared on the leaves of my vines; and 

 also on those which had been visited by the bug, in other places. I 

 suspected that these were the larvce of the C. vitivora, and we de- 

 stroyed all that we could find. By pursuing this course, in the spring 

 of 1832 and 1833, only a few bugs have been detected. 



In order to settle the question, which had arisen, whether these 

 worms were the larva of the C. vitivora, or not — in the summer of 

 1832 we put half a dozen of them into a tumbler, with moist earth, 

 and vine leaves, covering it closely. The earth was first carefully 

 examined to see that it harbored no other insect. Fresh leaves were 

 supplied, from time to time; and as the worms became full grown, 

 they passed, one by one, into the earth. After a fortnight or so, (for 

 the time could have been exactly determined only by appropriating 

 a glass to each worm), we found in the tumbler three perfect insects 

 of C. vitivora. 



This experiment, although not so complete as it might have been, 

 seems to leave but little room to doubt the indentity of the supposed 

 larva with this troublesome insect. 



For the information of those who cultivate the vine, that they 

 might be put on their guard against so dangerous an enemy, — most 

 of the foregoing details were published from time to time, in different 

 horticultural journals ; and I have now collected and arranged them 

 for the American Journal of Science, in order to inquire if this insect 

 has appeared in more distant parts of the United States, and wheth- 

 er or not, it had been previously described and published? 



2. Remarks on the specific character of Corydalis formosa and Co- 

 rydalis canadensis. 



Professor Eaton, in the last edition of his Manual of Botany, con- 



siders C. 



fi 



some slight difference produced by cultivation." I believe this opin- 

 ion has also been adopted by some other botanists ; and I therefore 

 enclose drawings made from each plant while in a living state. I 

 may add, that I have been acquainted with both for several years, 

 having cultivated them in my garden, although the former is indigen- 



