92 



SCIENCE 



[Vol. XVII. No. 419 



SCIENCE: 



WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES 



PUBLISHED BY 



N. D. C. HODGES, 



47 Lafayette Place, New York. 



Subscriptions. — United States and Canada $3.50 a year. 



Great Britain and Europe 4.50 a year. 



Communications will be welcomed from any quarter. Abstracts of scientific 

 liapersare solicited, and twenty copies of the issue containing such will be 

 mailed the author on request in advance. Rejected manuscripts will be 

 returned to the authors only when the requisite amount of postage accom- 

 panies the manuscript. Whatever is intended for insex-tion must be authenti- 

 cated by the name and address of the writer: not necessarily for publication, 

 but as a guaranty of good faith. We do not hold ourselves responsible for 

 any view or opinions expressed in the communications of our correspondents. 



Attention is called to the "Wants" column. All are invited to use it in 

 soliciting information or seeking new positions. The name and address of 

 applicants should be given in full, so that answers will go direct to them. The 

 " Exchange " column is litewise open. 



BROWN EOT IN GRAPES. 



In a bulletin soon to be issued by the Ohio Experiment Station, 

 Dr. C. M. Weed gives the following account of tlie downy mildew, 

 or brown rot, of grapes : — 



For many years the vineyardists of the great fruit belt in northern 

 Ohio along the southern shore of Lake Erie have been troubled by 

 a disease afifecting the foliage and fruit of the grape, called 

 "downy mildew," or "brown rot." At times this disease has 

 ruined nearly the entire crop, and has threatened to desti'oy the 

 vineyard industry over a large area. Fortunately, however, this 

 disaster has been averted by the discovery of a method by which 

 the disease can be largely or entirely prevented at comparatively 

 slight expense. 



The downy mildew, or brown rot, of grapes is a fungous disease ; 

 that is, it is a diseased condition of the foliage or fruit, due to the 

 presence of a fungus. This fungus is a minute parasitic plant 

 that develops at the expense of the tissues of the grape, thus caus- 

 ing blighting of the leaf, and decay of the fruit. It is distributed 

 over nearly the entire eastern half of the United States, and oc- 

 curs upon both the wild and cultivated varieties of grapes. It 

 probably lived upon the former before the introduction of the 

 latter. It attacks all the green parts of the vine, including the 

 young shoots, as well as the leaves and berries, and, like other 

 fungi, reproduces by means of spores. — minute bodies correspond- 

 ing in function to the seeds of flowering plants. 



When one of these spores falls upon a leaf where there is 

 sufficient moisture, it germinates by sending out a little tube, — 

 something as a kernel of corn in moist soil sends out its germinat- 

 ing radicle, — and this tube penetrates the epidermis, or skin, of 

 the leaf. Once inside, the tube continues to grow, pushing about 

 between the cells of the leaf, and forming what is called the 

 mycelium or vegetative portion of the fungus, which may be 

 likened to the roots of higher plants. As there is little nourish- 

 ment to be obtained between the cells, this mycelium develops 

 minute processes, vfhich push through the cell walls and absorb 

 the contents. 



After this mycelium has developed in the leaf for some time, it 

 is ready to produce its spores. Consequently it sends out through 

 the breathing-pores, or stomata, of the leaf, its fruiting branches. 

 These bear upon their tips small oval bodies, which are the spores. 

 The " mildew," which is visible to the naked eye, is composed of 

 these fruiting branches and their spores. It only develops under 

 certain atmospheric conditions, so that the mycelium may exist 

 in the aflfected parts of the vine for some time before this out- 

 ward manifestation of its presence occurs. This is the reason 



that a vineyard may apparently be "struck" with mildew in a 

 single night. 



Besides the spores above described, which are produced during 

 the summer season, and consequently are called summer spores, 

 there is developed in the fall a different class of spores by which 

 the fungus passes through the winter. Hence these latter are 

 called the winter spores. 



A knowledge of the method of development of the fungus 

 makes it evident that it cannot be reached after it has penetrated 

 its host. Consequently remedial treatment must be limited to 

 destroying the spores, and preventing their ingress to the tissues 

 of the plant. The experience of the last few years has shown that 

 this can be successfully accomplished by spraying the vines with 

 dilute solutions of certain salts of copper, particularly sulphate of 

 copper, or blue vitriol. 



Experiments with these copper compounds as preventives 

 of the several fungous diseases of the grape have been in 

 progress in France for a number of years, and have been attended 

 with remarkably successful results. The subject was taken up in 

 America about the middle of the last decade, and wonderful 

 progress has since been made. The Ohio station feels largely in- 

 debted to the United States Department of Agriculture for the 

 results obtained, especially to Messrs. Scribner and Gallovray, who 

 have had the work in charge. In Ohio the first experiments 

 were apparently made by Mr. George M. High, of Ottawa County, 

 who for the last five years has tested the remedies thoroughly, 

 and has triumphed over the unprogressive growers who were con- 

 tent to iet the disease destroy their crops rather than try any new- 

 fangled methods of checking it. 



THE NAME "AMERICA.'^ 



At the eighth international congress of Americanists, which 

 was held in Paris from Oct. 14 to Oct. 20, 1890, only a certain 

 number of the questions treated were of interest from a geograph- 

 ical point of view. Among these maybe mentioned the discussion 

 on the origin of the name •' America," which was opened by M. 

 Jules Marcou, who asserted, as we learn from the " Proceedings 

 of the Royal Geographical Society," London, that the name 

 " America " was derived from a range of mountains in Central 

 America, which, in the language of the natives, is called "Amer- 

 ique;" and that Vespucci never bore the Christian name of 

 " Amerigo," because this latter is not a saint's name in the Italian 

 calendar; and, further, ihat he changed his name " Alberico" to 

 " Amerigo " for the first time after the name by which the New 

 World is now commonly known began to be used, in order to cause 

 it to be believed that the continent was so named in his honor. 

 But M. Govi proved two years ago that the name " Alberico " is 

 in the Florentine language identical with •' Amerigo; " and that 

 Vespucci, before the year 1500, sometimes subscribed himself 

 " Amerigo " appears from a letter recently discovered among the 

 archives of the Duke of Gonzaga at Mantua. This point was cor- 

 roborated by the Spanish- Americanist, De la Espada, from letters 

 and pamphlets preserved in the Archiv de las Indias at Seville, in 

 which Vespucci sometimes calls himself " Alberico," and some- 

 times ''Amerigo." En passant, the Spanish savant mentioned 

 the interesting fact that the first of the so-called " quatuor navi- 

 gationes " was not made by Vespucci at all. 



M. Hamy adduced a further interesting proof of the incorrect- 

 ness of M. Marcou"s contention, in the shape of a map of the 

 world prepared in the year 1490 by the cartographer Vallescu of 

 Mallorca, on the back of which is a note to the effect that the 

 map was bought in at an auction by the merchant Amerigo Ves- 

 pucci for 1'30 gold ducats. Further, the general secretary of the 

 congress, M. Pector, pointed out, that, according to a communication 

 received from the president of Nicaragua, the range of mountains in 

 question is not called " Amerique " at all, but " Amerisque." After 

 this very thorough discussion of the question, it is to be hoped 

 that the accusations against Vespucci and Hylacomylus may not 

 be heard of again. An important contribution to the cartography 

 of America was furnished by the paper read by M. Marcel upon 

 two globes discovered by him, which date back probably from the 

 year 1513. 



