No. 2, September, 1920] PALEOBOTANY 259 



Vcllerea also has a higher percentage of crude fiber. The soluble portion of the fiber is Q01 

 cellulose, but, more than likely, hemicellulose. The chief difference consists in the greater 

 resistance of the cell walls of vcllerea, which makes it more difficult for digestive juices to at' 

 the nitrogenous constituents and albumen bodies (which are more abundanl in velh rea I 

 in piperita) in I his variety. It has not been definitely determined whal causes this difficult 

 permeability; it may be chitin. In general, the differences may be traced back with .sonic de- 

 gree of probability to the tomentose elements of the cap and to the large number of fertile 

 elements resulting from dense-growing lamellae. — ./. Roeser. 



197G. Sch0yen, T. II. Betydningsfulde nyere unders0kelser over furuens blaererust. 

 [Important new investigations on Peridermium pini.] Tidsskr. Skogbruk 28: 28-29. 1920. 



1977. Seaver, F. J. Notes on North American Hypocreales — IV. Aschersonia and Hypo- 

 crella. Mycologia 12 : 93-98. PI. 6. 1920. — Aschersonia is considered as the imperfect stage 

 of Hypocrella. On this basis a new combination, Hypocrella turbinata (Berk.), is made. H. 

 disjxmcta sp. nov. said to occur on white fly is briefly described and the belief expressed that 

 species of Hypocrella may prove to be of economic importance in combating harmful insects. 

 — 77. R. Rosen. 



PALEOBOTANY AND EVOLUTIONARY HISTORY 



E. W. Berry, Editor 



1978. Baccarint, P. Intorno all'ologenesi. [Concerning ologenesis.] Nuovo Gior. Bot. 

 Ital. 26: 115-128. 1919. — Daniele Rosa in his recent book "New theory of evolution and the 

 geographic distribution of life," makes an attempt to give on the basis of ologenesis a better 

 explanation of evolution and the distribution of plants and animals than could be had from the 

 theories of Darwin, Lamarck and de Vries. In brief, these are the writer's contentions: (1) 

 The evolution of the specific idioplasm, which is bound up with the phylogeny of the organisms, 

 is predetermined, continuous and independent of external factors. (2) The evolution of the 

 idioplasm is rectilinear up to a certain point when due to increasing complexity the idioplasm 

 divides dichotomously which results in the complete elimination of the mother form and the 

 establishment of two new "species" which in turn develop and then divide. (3) The evolution 

 is not reversible because the products of a dichotomous division have a different constitution 

 since, as was stated above, a certain part of the characters of the mother form have become 



B 



completely eliminated A = — . (4) Each new "phyletic species" (the complex of individuals 



lying between two dichotomous divisions) stands at the end of the genealogical tree and con- 

 sequently its phylogenetic prospects are much reduced. Furthermore, there is a tendency, as 

 evolution proceeds, for the new forms to become stabilized so that new dichotomous divisions 

 occur only at great intervals. Phyletic and systematic species are not identical. The former 

 has but a limited duration, although throughout its existence it may pass through a number 

 of different stages which would be considered distinct species, or even genera, by the sys- 

 tematist. (5) The large branches of the evolutionary tree are to be sought in the early geo- 

 logical ages when the phylogenetic prospect of the idioplasm was at its prime. The creation 

 of new forms, due to the dichotomous divisions of the idioplasm, does not alwa3 r s find immedi- 

 ate expression because of external conditions. A "mollusk," for example, may have been 

 potentially a mollusk long before climatic and environmental conditions permitted of the 

 existence of mollusks. This indicates why there is such a lack of connections in the evolu- 

 tionary line, and why there is such an apparent polymorphism. (6) Since the division of the 

 idioplasm of a given form took place simultaneously in all individuals and throughout the 

 entire area occupied bj r them, it becomes an easy matter to account for the geographic distri- 

 bution of species and to explain geographic anomalies without having to resort to the migra- 

 tion hypothesis. (7) In the development of the two species of a dichotomous division one 

 form may advance more rapidly and soon reach the apex of its development, while the other, 



