244 



SCIENCE 



[N. S. Vol. XLVI. No. 1184 



size of the leaves has little influence, if they 

 are relatively old, those less than one tenth 

 normal size having taken the disease in a 

 manner characteristic for the host species. 



In many cases inoculations have been made 

 with sBciospores as well as with uredospores, 

 similar results being obtained upon the same 

 host. In most cases both uredinia and telia 

 were produced. It has been impossible thus 

 far to have all the species authoritatively 

 identified, that being done as fast as the devel- 

 opment of the plants will permit. Therefore 

 this list is subject to such changes as further 

 study of the plants may cause. The syn- 

 onymy of the group is based, for the ISTorth 

 American species, on Ooville's treatment in 

 " ISTorth American Flora," issued by the New 

 York Botanical Garden, and for the species 

 of the rest of the world on Janczewski's "Mono- 

 graphie des Grosseilliers, Bibes L." and sup- 

 plements to that work. 



Successful inoculations have been made 

 upon the following species : Bibes alpestre 

 Dec, B. alpinum L., B. americanum Mill., 

 B. aureum Pursh, B. hracteosum Douglas, 

 B. carrierei hybrid, B. cereum Douglas, B. 

 coloradense Coville, B. cruentum Greene, B. 

 culverwellii hybrid, B. curvatum Small, B. 

 cynosbati L., B. diacantha Pallas, B. divari- 

 catmn Douglas, B. erythrocarpum Coville & 

 Leiberg, B. fasciculatum Seib. & Zucc, B. 

 fontenayense hybrid, B. futurum hybrid, B. 

 giraldii Janczewski, B. glandulosum Grauer, 

 B. glutinosum Bentham, B. gordonianum hy- 

 brid, B. hesperium McClatchie, B. hirtellum 

 Michaus, B. holosericeuni hybrid, B. inebrians 

 Lindley, B. inerme Eydberg, B. irriguum 

 DoxTglas, B. lacustre (Persoon) Poir., B. lep- 

 tanthum Gray, B. lohbii. Gray, B. menziesii 

 Pursh, B. missouriense Nuttall, B. monti- 

 genum McClatchie, B. nevadense Kellogg, 

 jB. nigrum L., B. nigrum var. aconitifolium,, 

 B. odoratum Wendl., B. oxyacanthoides L., 

 B. petraeum Wulf., B. reclinatum L., B. 

 rotundifolium Michaux, B. sanguineum Pursh, 

 B. setosum Lindley, B. speciosum Pursh, B. 

 succiruhrum hybrid, B. triste Pallas, B. vis- 

 cosissimum Pursh, B. vulgare Lam. 



Successful inoculations have been made on 



numerous unidentified Bibes from all parts of 

 the United States, including over one hundred 

 collections made by R. K. Beattie in the 

 Northwest and Pacific Coast States. Thus 

 far no species has proved to be entirely resist- 

 ant to the rust. 



The writers acknowledge the aid of the fol- 

 lowing in carrying on these experiments and 

 thank them for so kindly furthering the work : 

 Mr. E. K. Beattie, Dr. G. E. Lyman, The 

 Arnold Arboretum, The Forest Service and 

 The Office of Horticultural and Pomological 

 Investigations, Bureau of Plant Industry, 

 United States Department of Agriculture. 



Perley Spaulding, 

 G. Flippo Geavatt 

 Office of Investigations in 

 ToEEST Pathology, 

 Bureau of Plant Industry, 

 Washington, D. C. 



THE AMERICAN PHILOSOPHICAL 

 SOCIETY. II 



Naming American hyirid oaTcs: William Tee- 

 lease, Sc.D., LL.D., professor of botany. Uni- 

 versity of Illinois, Urbana. 



Thirty-eight known or probable hybrids among 

 the oaks of the United States have been brought 

 together from various and much scattered publi- 

 cations. No cases are believed to exist in which a 

 species of the white oak group (Leucoialanus) has 

 intercrossed with a species of the red oak group 

 {Erythroialanus) . To the 38 accepted hybrids al- 

 ready recorded, two are added in this paper — 

 X Quercus palceolitliicola (a cross between Q. 

 ellipsoidalis and Q. velutina), and Q. Schuettei (a 

 cross between Q. bicolor and Q. macrocarpa). Of 

 the 40 recognized hybrids, 15 have been given 

 binomials by earlier writers: the remaining 25 are 

 here named for the first time, in accordance with 

 international rules of procedure. 

 The wild relatives of our cultivated plants and their 

 possible utilization : W. T. Swingle, Ph.D., U. S. 

 Department of Agriculture. (Introduced by 

 Dr. William P. Wilson.) 

 An annotated translation of de Schweinitz's two 

 papers on the rusts of North America: Joseph 

 C. Aethuk, professor emeritus of botany, Pur- 

 due University, Lafayette, Indiana, and G. R. 

 BiSBY. (Introduced by Professor John M. 

 Coulter.) 



