Reviews — Dr. K. Glinka — The Soils of Russia. 563 



X. — IIesins in Paleozoic Plants and in Coals of High Rank. 



Ey David "White. United States Geological Survey, Professional 



Paper 85e, pp. 65-96, pis. ix-xiv, 1914. 

 rpHE importance of resins in the formation of Palaeozoic coals is 

 J_ shown to be as great as in later periods. The abundance of 

 resinous spores in Carboniferous times is well known, and in petrified 

 material we see that many Carboniferous plants were provided with 

 secretory canals and cells, the residues in which often suggest resins. 

 Certain carbonized fragments of petioles and wood from the Coal- 

 measures of Montana were found to contain abundant needle-like 

 rods, which from their characters and mode of occurrence seem to 

 represent the resinous fillings of longitudinal canals. Minute 

 refractive bodies in coal have been described by Mr. James Lomax 

 and others as resins, while in coal from the upper Mississippi valley 

 the author discovered small lumps of resin which had persisted 

 almost unaltered. The author suggests that though the amount of 

 exuded resin in early times may have been small, it was abundantly 

 stored in canals. That resins have not been more frequently 

 recognized is due to the fact that they have been altered and 

 carbonized, and in this connexion the author describes the resins in 

 various Cretaceous and Tertiary coals, which have been found in all 

 stages of alteration consequent on the change of the coal itself from 

 peats and lignites to the bituminous types. 



XI. — The Soils of Russia. 

 Die Typen dee Bodenbildtjng, ihre Klassifikation und Geo- 

 graphische Verbreitung, von Professor Dr. K. Glinka, 

 Direktor des landvvirtsch. Instituts des Kaisers Peter I zu Woronesh. 

 pp. 365, with 65 text-figures and a coloured map. Berlin (Borntraeger), 

 1914. Price 17s. 



IT has long been known to workers in agricultural geology that 

 a great amount of most valuable work in soil-investigation is 

 being carried on in Russia. Occasionally portions of this have been 

 made accessible to Western readers, such as the well-known papers of 

 Sibirzev, communicated to the Geological Congress at Petrograd, 

 and some most valuable memoirs submitted to the Agro-geological 

 Congresses at Budapest and Stockholm. But in the case of the 

 greater part of this work publication in the Russian language is an 

 insuperable bar to its wider appreciation. Now, however, it has 

 happily occurred to Professor Glinka to issue a German translation 

 of his Russian lectures, illustrated by many figures and an admirable 

 soil-map of the Russian Empire. 



Briefly stated, the general thesis of the Russian soil-investigators 

 is as follows : that the determining factor controlling the character of 

 the soil is climate ; under given climatic conditions similar soils can 

 be formed from a great variety of different rocks. This is specially 

 noticeable in the case of the well-known Tchernosem or black earth 

 of Russia, a soil which maintains its fertility without manure for an 

 indefinite time. 



The soils of Russia may be divided into zones or belts, which, on 

 the whole, show a close parallelism to the climatic belts, running 



