184 TRANSACTIONS OF THE ILLINOIS 



Mr. McAfee — How far does the generation of young lice from unim- 

 pregnated females go ? 



Mr. Riley — We know that they multiply organically for a series of 

 generations, but in the end, the male element is sure to come in. 



Mr. Furness — Has it any similarity to the louse on the apple tree 

 roots ? 



Mr. Riley — There is great similarity of habit. 



Mr. Wier — What is Bisulphide of Carbon, and where can it be 

 had? 



Mr. Riley — Any wholesale druggist or chemist can supply it. 



A Member — Suppose we laid the roots quite bare, and then spread 

 some Paris green on them, would that have any effect ? 



Mr. Riley — It would not be practicable, and I will tell you why. I 

 have found them three feet below the surface, and where the fibrous roots 

 go they will be found. The next best thing was carbolic acid, and sub- 

 mersion. Then any substance spread on the ground when the insects are 

 traveling would kill a great many, but it would not kill all. You want a 

 remedy that will kill all the lice, or they will soon be just as numerous as 

 ever. 



Mr. Barler — What is their size ? 



Mr. Riley — About the i-iooth or 2-iooths part of an inch. They 

 are big enough to be seen, because they are of a bright yellow color ; but 

 the eggs, which are in clusters, are more easily seen than the lice. 



Mr. Greene — Has it increased in the extent of its depredations on 

 the vineyards ? 



Mr. Riley^I believe not. I believe it has been killing the vines, 

 and they have been dying from it for many years. We have nothing to 

 fear from it here. It will enable us to understand the failures that have 

 occurred in the past, and induce us to examine both vines and roots. 



Trichina Spiralis has caused many a death which we attributed to 

 something else. We now know when a patient does die from Trichina 

 Spiralis. We may prevent the disease of these vines, now that we know 

 the cause. 



A Member — Why is it more destructive in France than here ? 



Mr. Riley — Because they lack the natural parasites which we have here, 

 to keep it in check ; and secondly, their vines are more tender in character 

 than ours ; thirdly, because their vines have not been accustomed to the 

 disease. Diseases which, among civilized communities, have prevailed 

 many centuries, and become innocuous, when brought among other 



