458 Palaeontologie. 



the State in which he emphasizes the paleogeography, the paleozoic 

 plants as we may know them from their fossils, and the meager 

 data of plant paleoecology. A page is given to a geological scale of 

 Ohio formations and some Space to a review of the theories of the 

 formation both of coal and of petroleum. Berry. 



Dachnowski, A., The ProblemofXeromorphy in the Vege- 

 tation of the Carboniferous Period. (Amer. Jour. Sei. (IV). 

 XXXII. p. 33—39. 1911). 



Extensive studies of an Ohio bog have lead the author to ad- 

 vance the theory that the antiseptic quality of most bog water and 

 its toxicity in not due, as formerly supposed, to the rather ill-defined 

 "humus aeids" but to other chemical substances which bear no rela- 

 tion to aeidity and which are formed by the action of bacteria and 

 saprophytic fungi upon the decaying Vegetation of the bog. These 

 substances affect bog plants unfavorably by checking the absorptive 

 activity of the roots and the plants are accordingly driven to reduce 

 transpiration through development of xeromorphic struetures. Such 

 struetures are observed among the bog plants of the Carboniferous 

 age and the author suggests that they are doubtless developed to 

 meet the same soilwater adversities that are met by present day 

 bog plants in cool temperate regions. 



The author believes that the assignment of warm climate to the 

 Carboniferous age was heterofore partly based upon these xeromor- 

 phic struetures and thinks that these struetures should not be corre- 

 lated with climate. Berry. 



Jeffrey, E. C, The affinities of Geinitsia gracillima. (Bot. Gaz. 

 LI. p. 21-27. pl. 8. 1911.) 



The author describes the anatomy of the cone-axis of the abun- 

 dant cones from the Upper Cretaceous long known as Sequoia gra- 

 cillima, referring them to the genus Geinitsia and giving certain 

 anatomical details which leads him to regard them as the cones of 

 an araucarian conifer. Berry. 



Knowlton, F. H., Description of two new fossil figs from 

 Wyoming and Montana. (Bull. Torrey bot. Club. XXXVIII. 

 p. 389—392. taf. 1—4. 1911.) 



Fossil fruits of the fig are by no means so common that the 

 two forms described in the present paper are not remarkable both 

 for their abundance and preservation. They are typical figs with 

 somewhat woody striated walls, the interiors of which became filled 

 with Sediments so that the fossils retain the pear-shaped form they 

 had in life. 



The species are Ficus Ceratops and Ficus Russelli and were 

 collected from the Lance formation, of Lower Eocene age , in Mon- 

 tana and Wyoming. Berry. 



Knowlton, F. H., Flora of the au rifer ous gravels of Cali- 

 fornia. (In: Lindgren, U. S. Geol. Surv., Prof. Paper 73, p. 57—64. 

 1911). 



The age of the auriferous gravels of the Sierra Nevada in 

 California has been the subjeet of prolonged discussion. In the 



