No. 1, Mat, 1921] PATHOLOGY 73 



492. Reid, E. M. Recherches sur quelques graines pliocenes du Pont-de-Gail (Cantal). 

 [Studies of Pliocene seeds from Pont-de-Gail, Cantal.] Bull. See. Geol. France IV, 20: 48-87. 

 PI. S-4. 1920.— Total number of varieties reported is 48 of which 37 are positively determined 

 and 17 of these are new and include species of Sparganium, Stratiotes, Carpinus, Fagopy- 

 rum, Ranunculus, Menispermum, Polanisia, Myriophyllum, Symplocos, Lycopus, Sambucus, 

 Trichosanthes and a new genus, Diclidocarya, of unknown botanical aflBnity and also present 

 in the Pliocene of Holland. The age is considered to be lower Pliocene and the flora contains 

 a large exotic and e.xtinct element with a pronounced southeastern Asiatic and North Ameri- 

 can facies. There is an elaborate discussion, the gist of which has already been given in the 

 abstract of this author's subsequently published paper on Pliocene floras. A complete 

 bibliography and two plates complete the paper. — E. W. Berry. 



493. Reid, E. M. Recherches sur quelques graines pliocenes de Pont-de-Gail (Cantal). 

 [A study of the Pliocene seeds of Pont-de-Gail.] Compt. Rend. Sommaire Soc. Geol. France 

 6: 49-51. 1920.— Seeds of 48 species of plants from the lower Pliocene of Central France are 

 recorded. Of these, 18 are new and 5 are exotics now dwelling in southeastern Asia. A 

 detailed account is promised in a future publication. — E. W. Berry. 



494. Stopes, M. C. Paleobotany in 1918. Sci. Prog. [London] 14: 39&-398. 1920.— A 

 brief review of the most important papers published in this field during 1918.— J. L. Weimer. 



495. Thiessen, R. Structure in Paleozoic bituminous coals. U. S. Bur. Mines Bull. 117. 

 896 p., 160 pi. 1920.— This paper gives the results of several years study of coal structures. 

 A historical summary is followed by an account of the methods of study. The origin and 

 structure of modern peat is discussed and it is shown that coal had a similar origin and shows 

 comparable structure and plant content. The coals described in detail comprise samples 

 from Pennsylvania, West Virginia, Indiana, Illinois, Iowa, and Alabama, all from bitu- 

 minous mines and of Carboniferous age. Coal is shown to consist of the three elements long 

 recognized, namely, the charcoal, or "mother of coal," and compact coal, the latter con- 

 sisting of alternating laminae of dull coal (matt, cannelloid, sapanthrakon) and bright bands 

 (glanz, humus, jet, carbohumin, lignitoid, hydrocarbon), the anthraxylon of the author. The 

 dull laminae are shown to be made up of former woody parts in a more finely divided state 

 than in the bright bands and imbedded in a ground mass of finely divided debris which the 

 author calls the attritus. The attritus consists chiefly of woody degradation products along 

 with traces of cuticles, spore and pollen exines, and resinous particles of various origins. 

 The bright laminae are shown to consist largely of small chips of semi-decayed woody tissues. 

 Many plant fragments of various plant parts and a variety of exines are discussed and fig- 

 ured but no attempt is made to assign names to any of them except a Medullosa stem, which is 

 identified as Medullosa anglica. The report is profusely illustrated.— JS?. W. Berry. 



PATHOLOGY 



G. H. Coons, Editor 

 C. W. Bennett, Assistant Editor 



(See also in this issue Entries 8, 15, 25, 54, 158, 173, 181, 386, 397, 456, 459, 475, 476, 482, 



483, 611, 612, 675, 678, 682, 688) 



PLANT DISEASE SURVEY; REPORTS OF DISEASE OCCURRENCE AND SEVERITY 



496. Anonymous. Chemistry in plant distribution. Sci. Amer, Monthly 1 : 562-563. 

 1920. — The use of methyl red to indicate whether or not a soil is suflSciently acid to grow scab- 

 free potatoes is explained, — Chas. H. Otis. 



497. Arthur, J. C. Two destructive rusts ready to invade the United States. [Abstract.] 

 Phytopath. 10:65-66. 1920. 



