OF THE STATE ENTOMOLOGIST. 61 



goo.d entomologists, as Signoret, Boisduval and the late Gu6rin-Mene- 

 ville— men, however, whose records have earned for them the title of 

 impractical. When the Oidium first began to attack French vines the 

 last-named gentleman maintained that it had nothing to do with the 

 injury now so well known to be caused by it; but argued that the 

 vines were simply diseased from plethora of sap. So of that fearful 

 •silk-worm disease known as pi'hrine : long after the laborious and 

 painstaking Pasteur had analyzed it and shown that it is due to the 

 presence and multiplication of certain corpuscular psorospermioB^ 

 •Guerin-Meneville insisted that no importance could be attached to 

 the presence of these bodies. It is not surprising, therefore, that he 

 should have persisted in misconstruing the facts regarding Phylloxera, 

 and in believing that it is a "pathological condition of the vine which 

 has favored the increase of the insect." Yet the practical grape- 

 grower of to-day aims his sulphur remedies direct at the Oidium fun- 

 gus, knowing well that if he can prevent its multiplication he will pre- 

 vent the disease ; while the silkgrower labors for the prevention or 

 destruction of the psorospermice., knowing that without them his 

 worms will not suffer from pebrine. And so it will be with Phylloxera : 

 keep off or destroy the insect and you avoid the disease. We have in 

 all such cases a repetition of the noted itch controversy. For centu- 

 ries the work of Aoarus scahlei, was supposed to be a constitutional 

 malady, due to "thickened bile, " "drying of the blood," etc., and 

 iong after Dr. Bonomo gave us its true rationale, there were not want- 

 ing those who denied any connection between the mite and the dis- 

 ease, or who explained the presence of the former by abiogenesis, or 

 hy other equivocal means. 



The more plausible arguments that the Phylloxera disease is 

 ^caused by drouth, by too long continued cultivation of the same plant 

 from cuttings, too severe pruning, exhaustion of soil, etc., have all of 

 them fallen before the facts; and the poor grape-grower who, influ- 

 enced by them and regarding the Phylloxera with indifference, was 

 led to replace his dead vines by others, has been bitterly disappointed 

 in seeing these in time destroyed and his labor and outlay lost. 



If there were no other proof of Phylloxera being the cause of the 

 ■disease than that which I have lately obtained, it would be over- 

 whelming in contrast with the non-experimental views of the opposite 

 school. Conceiving that the question could be settled by a very 

 simple experiment, I planted in pots, in the spring of 1873, four one- 

 year rooted Catawba vines, all of a size and vigor, and the roots of all 

 ascertained to be free from Phylloxera. Two of these vines were, 

 •during the summer, kept out of the reach of infection; while, from 

 (time to time, I buried, in the other two pots, pieces of roots heavily 



