718 



SCIENCE 



[N. S. Vol. XXXI. No. 801 



lation experiments have been tried on sugar 

 cane but without success. The fungus would 

 grow, and also fruit to some extent, at the 

 point of inoculation, but would not spread 

 into the healthy tissue. 



C. W. Edgerton 

 Louisiana Aqbicultueai, 

 Experiment Station 



SOCIETIES AND ACADEMIES 



THE GEOLOGICAL SOCIETY OF WASHINGTON 



At the 229th meeting of the society, held at 

 the George Washington University on Wednesday 

 evening, March 9, 1910, informal communications 

 were presented as follows: 



Mr. Chas. A. Davis exhibited a map showing 

 the distribution of workable peat deposits in the 

 United States and their relation to the areas of 

 glaciation and heavy precipitation. 



Mr. E. G. Woodruff presented a diagram con- 

 structed from measurements made along an out- 

 crop of coal beds in central Wyoming, showing 

 their pronounced lenticular character. 



Mr. J. T. Pardee exhibited photographs and a 

 sketch map of the region covered by the former 

 glacial Lake Missoula, which once occupied some 

 4,'o00 square miles in the drainage basin of the 

 Clark Fork in northwestern Montana and was 

 dammed by a south flowing ice tongue of the 

 Cordilleran ice cap near Lake Pend d'Oreille. 



Regular Program 

 A Microscopical Study of some Sulphide Ores: 



F. B. Lanet. 



A Proposed Classification of Petroleum and Nat- 

 ural Oas Fields based on Structure: Fbedebick 



G. Clapp. 



The classification is a tentative one which was 

 evolved at least in part in order to illustrate to 

 oil operators the differences in geological condi- 

 tions in different fields. The main divisions of 

 the classification are as follows: (I.) Anticlinal 

 and synclinal structures; (a) strong anticlines 

 standing alone, (5) well-defined anticlines and 

 synclines alternating, (o) monoclinal slopes with 

 change in dip, (d) terrace structures, (e) broad 

 geanticlinal folds. (II.) Domes, or quaquaversal 

 structures (Salines). (III.) Sealed faults. 

 (IV.) Oil and gas sealed in by asphaltic deposits. 

 (V.) Contact of sedimentary and crystalline 

 rocks. (VI.) Joint stacks. 



As examples of subclass I. (a), the fields on 

 the Eureka- Volcano-Burning Springs anticline of 



West Virginia and certain California fields are 

 given. In subclass I. (6) are placed most of the 

 fields related to anticlines and synclines in the 

 Appalachian province, the Caddo field of Louisi- 

 ana, the Coalinga and Los Angeles fields of Cali- 

 fornia and the Burma and other well-known fields 

 in other countries. The majority of the oil and 

 gas pools of southeastern Ohio belong in division 

 I. (c), or in I. [d] which is an exaggerated form, 

 of I. (o). The best example known of subclass 



I. (e) is stated to be the extensive field on the 

 Cincinnati anticline in Ohio and Indiana. Class 



II. includes the fields of the gulf coastal plain. 

 Class III. is exemplified by certain pools in the 

 Lompoc field and perhaps other fields of southern 

 California. Class IV. is somewhat hypothetical, 

 so far as oil and gas accumulations of economic 

 value are concerned, but it may be exemplified 

 by the pitch lake of Trinidad. Class V. is known 

 to exist in the Province of Quebec and to some 

 extent in northern New York state, where natural 

 gas is found in the arkose zone of the Potsdam 

 sandstone resting on prominent knobs in the 

 underlying crystalline rocks. Class VI. was added 

 after the discussion in accordance with a sugges- 

 tion by Mr. M. R. Campbell. An example of it 

 is a part, at least, of the Florence oil field in 

 Colorado. In illustrating the proposed classifica- 

 tion, several notable deficiencies in past assump- 

 tions of geologists and oil operators were men- 

 tioned, and the lessons to be drawn from them in 

 the light of recent developments were emphasized. 



Some Notes on the Mammoth Cave, Kentucky: 



James H. Gardner. 



The Mammoth Cave is essentially a product of 

 solution in the St. Louis Limestone, which in this 

 section of Kentucky is about 500 feet thick. 

 Meteoric waters charged with carbonic acid gas 

 began permeation of joint planes in the limestone 

 as soon as Green River had cut its channel 

 through the Kaskaskia sandstone into the St. 

 Louis. In the opinion of the speaker these joints 

 were produced by pressure exerted from the Cin- 

 cinnati Arch either by movements of uplift or 

 subsequent settling. The drainage of this section 

 of Kentucky is chiefiy underground where the 

 St. Louis is the surface rock and the formation 

 is one abounding in subterranean caverns. 



The present entrance to the cave, which is in 

 the hills bordering the east banks of Green River, 

 is doubtless the original exit of Echo River, 

 though this stream has found lower outlets from 

 time to time and is now about 195 feet below this 

 level. Writers on the cave have considered this 



