December 7, 1900.] 



SCIENCE. 



875 



known from any one locality of the conti- 

 nental "North American Tertiaries. How- 

 ever, the state of preservation of the speci- 

 mens is not always satisfactory, and it may 

 not be possible specifically to describe all 

 of them. 



The particular interest of this fauna does 

 not lie in its richness, but in its geologic 

 import. The Tertiary coral faunas of the 

 United States below the Chipola horizon 

 were very isolated, no species from the con- 

 tinent, excepting the Orbicella mentioned, 

 being found in any other area. This fauna 

 is distinctly Antiguan in types. Besides 

 the Orbicella referred to, there is a very 

 large- celled Orbicella, very close to 0. crassi- 

 lamellata (Duncan), if not identical with 

 that species, found abundantly at Russell 

 Spring. An Astroccenia is extremely close 

 to A. ornata of Duncan from Antigua. The 

 same remark will apply to the Stylophora 

 and Alveopora. 



Prom this field examination it appears 

 that the reef corals of the Antiguan marls 

 and cherts can be correlated with the base 

 of the Chattahoochee limestone, the base 

 of Dall's Upper Oligocene. It is also quite 

 probable that the Oligocene reefs in the 

 vicinity of Lares, Porto Rico, and of Serro 

 Colorado, Curagao, represent the same hori- 

 zon. The Bowden, Jamaica, fauna would 

 be slightly higher, to be correlated with the 

 Chipola fauna. 



It is evident that this coral fauna from 

 Russell Spring, besides filling a gap in the 

 faunal succession on the continent, fur- 

 nishes a basis for correlating many of the 

 West Indian fossil reefs with the conti- 

 nental Tertiary section, and we may confi- 

 dently expect more light upon the correla- 

 tion of American and European horizons. 



One interesting feature of these corals, 

 not already mentioned, is that they appar- 

 ently bring the fauna of Vicksburg, Mis- 

 sissippi, into closer relation with the suc- 

 ceeding faunas. A great deal is shown 



regarding the succession and interrelations 

 of the faunas of the continent itself. 



A fossil coral reef is always interesting, 

 as it reveals in an accurate manner the 

 physical conditions prevailing in a region 

 during a certain portion of its geologic 

 history. 



When the material collected has been 

 carefully studied in the office, a detailed 

 account will be published. 



T. Wayland Vaughan. 



Bainbridge, Ga., Nov. 3, 1900. 



PEACH YELLOWS: A CAUSE SUGGESTED. 

 Some scientific problems lie beyond the 

 reach of present knowledge, in the sense 

 that they are inaccessible through combi- 

 nations of known facts or methods of re- 

 search ; in dealing with such matters specu- 

 lation is permitted full sweep in the hope 

 that some hypothesis may point the way 

 to experimental effort and demonstration. 

 There are, however, other questions to 

 which it seems that ascertained facts should 

 furnish a sufficient clue, though the solu- 

 tion may long elude us. With regard to 

 these, speculation appears to have less pro- 

 priety, perhaps because we have learned to 

 expect more from increased skill and im- 

 proved methods of research than from 

 theoretical considerations. But if one of 

 these apparently ripe fruits of knowledge 

 refuses to fall, the efi'orts of the investigat- 

 ing scientists take on added interest, and 

 the bystanders may become anxious to tell 

 just how it should be done. Thus far these 

 well-intentioned people have not been per- 

 mitted much satisfaction in connection 

 with the mystery of the peach-yellows, the 

 vigorous and sustained attack by the first 

 investigator, Dr. Erwin F. Smith,* hav- 

 ing left untried no theory or method which 

 had been applied in previous studies of 



* Dr. Smith's results were finally summarized in 

 Farmer's Bulletin No. 17, U. S. Department of 

 Agriculture, 1894. 



