152 abstracts: heredity 



MINERALOGY. — The crystallography of natramblygonite. Walde- 



MAR T. ScHALLER. Zeits. f. Krystallographie und Mineralogie, 



51: 246-247. 1912. 



Crystals of natramblygonite (Na[Al(0H,F)]P04) from Canon City, 



Colorado, are described. They are very close to those of amblygonite 



in their interfacial angles and show similar crystal forms. W. T. S. 



ECONOMIC GEOLOGY. — The commercial marbles of western Vermont. 

 T. N. Dale. Bulletin 521, U. S. Geological Survey, pp. 164 and 

 index, 2 colored geological maps, with sections, views, diagrams and 

 micro-drawings, 1912. 

 Altho this bulletin has to do mainly with the calcite and dolomite 

 marbles it includes brief accounts of the Roxbury serpentine and the 

 newly discovered chrome-mica schist marble of Shrewsbury. It com- 

 prises a brief manual on marble in general, an account of the local areal, 

 structural and historical geology, and the economic application of 

 stratigraphy and petrography to the marble industry. In the scientific 

 part the origin of dolomite is discussed and new facts are adduced to 

 show that altho dolomitization of CaCOs does occur some dolomite is 

 probably of direct sedimentary origin. In the economic part the Ver- 

 mont marbles are standardized as to texture by their average grain 

 diameter by the Rosiwal method and are compared with various Euro- 

 pean marbles. All the marbles described are classified commercially 

 and scientifically. There are also chapters on values, adaptations, 

 marble machinery, the probable amount of unexplored marble in western 

 Vermont, scientific prospecting for and the testing of marble. Three 

 bibliographies of marble are given, scientific, economic, and local, also 

 a glossary of technical terms. T. N. D. 



HEREDITY. — Heredity and cotton breeding. 0. F. Cook. Bulle- 

 tin 256, Bureau of Plant Industry, pp. 113, 6 plates, 19 text figures. 

 1913. • 

 This bulletin attempts to present a more concrete conception of the 

 nature of heredity, and to utilize this conception in the elucidation of 

 practical breeding problems. Many current ideas of heredity derived 

 from the study of self-fertiHzed plants are not applicable to normally 

 open-fertilized types like cotton and corn. In dealing with such plants 

 the "pure line" conception of heredity as represented by a conchtion of 

 uniformity and stability of characters should give place to a recognition 

 of diversity and free interbreeding as the normal antecedent condition 

 of heredity and of evolutionary progress. 



