Kv PROCEEDINGS OF THE 



reach of every intelligent cultivator. But within the last few years 

 a new plague has in the south of France excited even more alarm 

 than the oidium itself, from its insidious invasion and complete de- 

 struction of many of the most valuable vineyards ; this time, how- 

 ever, the offending parasite is brought much more within the scope 

 of direct scientific observation. The germs of the potato-fungus, of 

 the pebrine, of the oidium are all invisible and inappreciable by any 

 of our instruments ; the history of their diff'usion and early develop- 

 ment, and even their very existence can only be judged of from 

 their results and other circumstantial evidence ; whilst the Phylloxera 

 vastatrix can be watched in every stage of its varied existence, from 

 the first deposit of the fertilized eggs, through its several agamic 

 generations, to the latest winged form. The researches, accordingly, 

 which have been already applied to it have not been altogether 

 barren of results, throwing some light even generally upon the origin 

 and dispersion of these pests. Considerable sums of money, either 

 from the French Government or from private subscriptions, have 

 been applied to the purpose ; and the investigation has been chiefly 

 carried on by our foreign member, Dr. J, E. Planchon, of Montpel- 

 lier, assisted by M. J. Lichtenstein, a relative, I believe, of the late 

 distinguished Prussian zoologist. These gentlemen, since the first 

 discovery of the disease in France in 1868, have devoted much of 

 their time to it. They have compared their observations with those 

 of others, who in other countries have studied the insect, especially 

 Mons. Laliman, of Bordeaux, Mr. Riley, of Missouri, and Prof. 

 Westwood in our own country ; and they have now, in a pamphlet 

 which, by some inversion of dates not uncommon abroad, is supposed 

 to form part of the Proceedings of the session of the French scien- 

 tific congress at Montpellier in 1868, given a resume of nearly five 

 hundred memoirs, communications, or journal articles which have 

 been published on the subject up to the close of last year (1871). 



The main facts given as having been hitherto elicited as proved 

 or probable may be shortly resumed as follows: — 



The Phylloxera, like other Aphides, goes through a number of 

 apterous generations of a single sex, but multiplying with enor- 

 mous rapidity ; for one or two individuals will lay as many as five 

 hundred eggs, fertilized without previous copulation. It also gives 

 birth occasionally to a winged generation of both sexes, the females 

 of which lay only two or three eggs each. 



The apterous Phylloxera is also dimorphous : — a smooth-bodied 

 form living in little galls formed on the leaves of the vine, where it is 



