110 



SCIENCE 



[N. S. Vol. XLIII. No. 1099 



[In the reviewer's opinion this jaw agrees in 

 most of its characteristic features with the 

 Leptictidse, a family of Insectiyora, and the 

 single feature of resemblance to Myrmecohius, 

 the relative height of inner and outer trigonid 

 cusps is by no means sufficient evidence for 

 relationship to the marsupials. The tooth con- 

 sidered by Mr. Gidley to be the first molar ap- 

 pears to the reviewer to be clearly a fourth pre- 

 molar, as it is set deeper in the jaw and less 

 worn than the tooth behind it, belongs there- 

 fore to the successional series or premolars, 

 not to the first series of cheek teeth (milk and 

 true molars), and is characteristically like the 

 fourth premolar of all the Leptictid genera, 

 especially that of an undescribed genus from 

 the Paleoeene (Torrejon formation). The 

 skull and skeleton characters of Myrmecohius 

 are, on the other hand, in near agreement 

 throughout with the polyprotodont marsupials, 

 and wholly at variance with Gidley's con- 

 clusion of an independent parallel evolution of 

 the group from pre-Tertiary ancestors. 

 W. D. M.] 



An important monograph by Professor H. 

 Winge,^^ of Copenhagen, upon the Edentata of 

 the Pleistocene of Brazil includes an authori- 

 tative systematic revision of the order, and 

 critical notes of great interest. 



Dr. O. Abel, of Vienna, has published a 

 small but richly illustrated book entitled " Die 

 vorzeitlichen Saugetiere." American fossil 

 mammals are exceptionally well represented. 



Under the title of " Climate and Evolution " 

 Dr. W. D. Matthew,*" of the American Mu- 

 seum of Natural History, presents a theory ac- 

 counting for the observed geographical dis- 

 tribution of animals in present and past ages. 

 He begins by applying to the facts certain 

 modern geological doctrines, such as the corre- 

 lated alternations of elevation and of climate 

 during geological time, the isostatic balance of 

 continental and ocean masses, and the persist- 

 ence of the great continental masses which 

 never sank to abyssal depths, but often per- 

 mitted the sea to make temporary incursions 



39"Aftryk af 'E Museo Lundii' Kobenhaven, " 

 1915. 



40 Annals N. T. Acad. Sci., Vol. 24, 1915. 



upon their surfaces. Partly by means of a 

 remarkable series of maps, showing the present 

 and past distribution of many races of mam- 

 mals, the author adduces very weighty evi- 

 dence for the view that these races originated 

 in the northern continents and then spread 

 southward into South America, Africa, south- 

 eastern Asia and Australia. 



Professor H. F. Osborn,*'^ of the American 

 Museum of ISTatm-al History, contributes to 

 the American Naturalist an extended study of 

 certain features of the process of evolution. 

 Basing his conclusions on a wide range of 

 zoological, experimental and paleontologieal 

 data, he develops the distinction between 

 " rectigradations," or qualitatively and nu- 

 merically new characters and " allometrons," 

 or changes in proportion, degree or intensity. 



The same author*^ summarizes the suc- 

 cessive advances and retreats of the continental 

 glaciers and the corresponding shiftings of the 

 floras, faunas and human populations. The 

 special feature of this paper is the demonstra- 

 tion that in Europe, as in America, the so- 

 called " warm fauna " survives tmtil the ad- 

 vance of the fourth glaciation. The last topic 

 is more fully treated in Professor Osborn's 

 recently published work entitled " Men of the 

 Old Stone Age." Here the author gives a de- 

 tailed description and analysis of the long 

 series of Paleolithic stages in Europe, with a 

 series of new restorations of Pithecanthropus, 

 of Eoanthropus and of the Races of Neander- 

 thal and Cro-Magnon. 



0. E. Eastman, 

 W. K. Gregory, 

 W. D. Matthew 



SPECIAL ARTICLES 



A PHOMA DISEASE OF WESTERN WHEAT- 

 GRASS 



Western wheat-grass, Agropyron smithii 

 Eydb. is a very important forage plant in 

 many of the pastures in the Salt Lake Valley, 



41 American Naturalist, Vol. 49, April, 1915, 

 pp. 193-239. 



■42 ' ' Eevision of the Pleistocene of Europe, Asia 

 and Northern Africa," Annals N. ¥. Acad. Sci., 

 July, 1915. 



