280 



SCIENCE 



[N. S. Vol. XLVI. No. 1186 



having three of the above points in its favor, 

 namely, (1) structure, (2) water, (3) original 

 oil. There are numerous favorable structural 

 conditions in various counties of the state. 

 The rocks contain plenty of veater and there 

 are some good beds of oil-bearing shale. The 

 Devonian Black Shale is particularly a splendid 

 carrier of original oil. The fourth factor is, 

 however, as yet to be proved of sufficient im- 

 portance to place Kentucky in high rank as an 

 oil state ; namely, " sand." In great oil fields 

 there are large bodies of sand or retaining 

 reservoirs in close proximity to beds of oil- 

 bearing shale. There are frequently several 

 such " sands " in the geological column in close 

 relationships to oil-shale beds. 



In Kentucky the " sands " or " porous beds " 

 near the Devonian Oil Shale are carrying most 

 of the oil so far discovered. In Wayne County 

 these sands lie in the Waverly series above the 

 Black Shale, but in other districts the oil is 

 held below the shale in porous beds of lime- 

 stone. This is true of the oil fields at Irvine, 

 Cannel City, Campton, Menefee County and 

 other districts of eastern Kentucky. In the 

 coal basins of eastern Kentucliy and western 

 Kentucky there are a large number of beds of 

 porous quartz sandstone; they lie in the 

 Chester and Pennsylvania series, but in con- 

 nection with these sandstone beds, oil shales 

 must be proved to exist in order that any par- 

 ticular structure may be found productive. 

 If, for instance, a bed of oil shale like the 

 Devonian Black Shale could be found just 

 above or below the Big Clifty Sandstone at the 

 base of the Chester, then an anticline contain- 

 ing these beds at sufficient depth would most 

 certainly make a big oil and gas field like those 

 of Oklahoma; but it so happens that in a great 

 many cases in Kentucky the oil shales do not 

 lie near dependable porous reservoir rocks or 

 else the porous sandstones in the higher por- 

 tion of the geological column, such as those 

 above enumerated, do not have near them any 

 great amount of typical oil shale. 



In conclusion the writer desires to state it 

 as his opinion that Kentucky is not to rank 

 high as an oil state in comparison with many 

 other areas in the United States where the 



four factors work in harmony and there are 

 numerous porous sands near beds of oil shale; 

 however, the writer wishes to emphasize the 

 probability that a • number of structures in 

 Kentucky will find the four factors working 

 together and will furnish new oil pools that 

 will be highly valuable to those who are for- 

 tunate enough to discover them. 



Careful studies by geologists working in the 

 state will serve to gather a great deal of im- 

 portant information in addition to merely 

 mapping suitable structural conditions in any 

 particular locality. 



James H. Gardner 



Tulsa, Okla. 



OVERWINTERING OF THE APPLE- 

 SCAB FUNGUS 



Though it is generally knovsii that the scab 

 disease of the apple, caused by the fungus Ven- 

 turia inequalis, sometimes attacks the young 

 twigs of susceptible varieties of the apple, yet 

 not much has been published on this phase of 

 the disease in ISTorth America. 



Morse and Darrows^ show that the conidia 

 of this fungus survived the winter on apple 

 twigs and germinated readily in the spring. 

 They found no evidence, however, that the 

 mycelium exists during the winter as a living 

 stroma and produces conidia in the spring. 



A review of the literature of this subject is 

 given by Morse and Darrows. Wallace^ also 

 reviews the literature of the persistence of the 

 stroma on the twigs and the hibernation of 

 conidia and is convinced that twig infection 

 is not of common occurrence and that conidia 

 can not withstand winter temperatures. 



The writer's attention was first called to scab 

 disease on the young shoots of the apple in the 

 fall of 1915, when a number of badly diseased 

 twigs of a Mcintosh apple tree were sent to 

 the college for determination. They were 

 forwarded by Dr. E. W. Henderson, of Man- 

 sonville, in this province. The twigs were de- 

 foliated for several inches from the tips, and 

 the leaves that remained below showed a very 

 severe attack of scab. The twigs were severely 



1 Phytopath., 3 : 265, October, 1913. 



2 Bull. Cornell, 335, 193. 



