206 Physiologie. — Palaeontologie, 



the use of tor malin is of benefit, in that it effects a sort of seed 

 selection resulting in the partial eliminaüon of the poorest seeds. 



Moore. 



Stone,G.E., Influence of electricity on microorganisms. 

 (Bot. Gaz. XLVIII. p. 359—379. fig. 1—2. Nov. 1909.) 



Experiments with weak currents (0.1—0.8 milleamperes) as ^Yell 

 as sparks on yeast, and the bacteria of water, milk, and soils. No 

 attempt was made to find the strength of current necessary to pro- 

 duce the best results, but so far as possible what was considered 

 the Optimum strength was generall}?^ employed. Apparentl}' all the 

 forms worked with were stimulated by a current of optimum inten- 

 sity. The effects produced resemble more nearly those of heat, and 

 are manifested shortly after application. No attempt is made to solve 

 the Problem of the manner in which electricity stimulates organisms. 

 although it is suggested that it is probably associated with greater 

 metabolic activity, Moore. 



Jeffrey, E. C, A new Araucarian Genus from the Triassic. 

 (Proc. Bost. Soc. nat. Hist. XXXIV. p. 325—332. pl. 31, 32. 1910.) 



The author describes the structure of Woodworthia ayizoiiica 

 which is held to possess the wood structure of the living Araitca- 

 rieae as well as persistent Short shoots of the Abietineous type. The 

 authors conclusions are: First, that persistent leaftraces are not 

 ancestral coniferous characters. Second, that the Ahietineae repre- 

 sent the most primitive living conifers and Third, that short shoots 

 were probably a common feature of the older Coniferous stock. 



Berr\\ 



Knowlton, F. H., Jurassic age of the "Jurassic Flora of 

 Oregon". (Amer. Journ. Sei. IV. 30. p. 33—64. 1910.) 



This paper is a succinct summary of the bearing of the abun- 

 dant paleobotanical data monographed some years ago by Profes- 

 sors Ward and Fontaine upon the stratigraphj^ of the extensive 

 Mesozoic deposits in the Pacific coast province of North America. 



The vast thickness of deposits constituting the Knoxville beds, 

 amounting to 20,000 feet, have usuall)^ been considered Lower 

 Cretaceous in age by American paleontologists although the belief 

 that they are in part Jurassic has been expressed b}' both Professor 

 A. P. Pavlow and Professor Emil Hang. 



In a masterly discussion of the contained flora, which is abun- 

 dant, Dr. Knowlton shows that the Lower Cretaceous (Shasta) llora 

 embracing 60 species, indicaling a Neocomian age, ranges from the 

 Upper Knoxville through the Horsetown beds. The [true Jurassic 

 fxOra includes 100 species and ranges from beds which have been 

 referred to the Mariposa formation upward through the major 

 portion of the Knoxville beds. This Jurassic flora is closely allied 

 with Lower Oolitic floras of know stratigraphic position in other 

 parts of the world. Hence the transition from Jurassic to Lower 

 Cretaceous on the Pacific coast instead of being pre Knoxville 

 occured well toward the top of the latter series of deposits and is 

 fixed by the upper limit of the Jurassic flora. Berr)'. 



