490 



SCIENCE 



[N. S. Vol. XXXVI. No. 928 



deed be planted somewhat closer and the 

 yield correspondingly increased. 



A comparison of the nuts yielded by the 

 two varieties shows points of favor for each 

 one. The Mammoth nuts are much larger 

 and handsomer and would be more attractive 

 on the market. This is offset by the fact that 

 the shells are much thicker and the kernels 

 do not wholly fill the cavities but rattle around 

 loosely, while the Spanish peanut has a paper- 

 thin shell, closely surrounding the kernel, so 

 that there is no waste space. The kernel of 

 the Spanish peanut is short, almost like a 

 pea, and remarkably solid. 



An unexpected difference, much to the ad- 

 vantage of the larger peanut, lies in the labor 

 involved in shelling the nuts. The thin, close- 

 fitting shell of the Spanish peanut makes it 

 exceedingly hard to shell the kernels rapidly, 

 while this process is easy in the larger nuts. 

 The extra work required when the Spanish 

 nuts are to be shelled by hand more than off- 

 sets the ease in harvesting them. 



Which variety would be most desirable to 

 grow depends upon conditions. Where the 

 season was rather short the Spanish would be 

 better, and where the peanuts were raised for 

 pig-pasture it would be much superior, as the 

 only disadvantage of the Spanish nut, that of 

 the labor of shelling the kernels, would here 

 not be considered. 



The purpose of taking the diameter of the 

 nuts and kernels was to show the difference 

 in waste as regards cross-section. The shells 

 differed markedly in thickness, and this could 

 not be satisfactorily compared, as the irregu- 

 larities made such measurements of little 

 value in themselves; moreover, there was an 

 empty space between the kernel and shell of 

 the Mammoth variety to be taken into con- 

 sideration. The measurements of whole nuts 

 and kernels show that the diameter of the 

 kernel of the Mammoth peanut was about 58 

 per cent, that of the entire nut, while in the 

 Spanish peanut it was a little over 75 per 

 cent. 



H. Walton Clark 



Bureau of Fisheries Biological Station, 

 Faiepoet, Iowa 



contact action of gabbro on granite in 

 warren county, new tork.* 



While engaged in detailed field-work on 

 the North Creek (Warren county) New York 

 quadrangle, the writer found a fine example 

 of contact action of gabbro on granite, which 

 it is the purpose of this paper to describe. 



The rocks of the region are all pre-Cam- 

 brian and these, named in relative order of 

 ages, comprise the Grenville sedimentary 

 series of various gneisses, limestone, and 

 quartzite; the great syenite-granite intrusive 

 masses; gabbro stocks or dikes; pegmatite 

 dikes; and diabase dikes. The Grenville and 

 syenite-granite series are highly metamor- 

 phosed and clearly gneissoid; the gabbro is 

 only moderately metamorphosed; while the 

 pegmatite and diabase are wholly unaltered. 



The gabbro, which is of special interest 

 here, almost invariably occurs in the form of 

 small stocks or bosses (rarely as dikes) which 

 break through the country rock (Grenville, 

 syenite, or granite) in vertical, plug-like or 

 pipe-like forms which on the geologic map 

 show elliptical or nearly circular ground- 

 plans. The gabbros are generally medium to 

 coarse-grained, always holocrystalline, and 

 they show every evidence of having been in- 

 truded under true plutonic conditions. 



The contact metamorphism here described 

 may be seen at the southern end of the gabbro 

 stock (length | of a mile) which lies just 

 south of Mountain Spring lake or at a point 

 2 miles southwest of Pottersville. In a 

 recently opened stone quarry, about 75 feet 

 higher than the road on its east side, the rocks 

 are laid bare in such a manner as to afford an 

 excellent opportunity for the study of the con- 

 tact zones. 



The following nine zones, passing from the 

 typical gabbro to the tj^jical granite (country 

 rock), have been studied in detail in the field 

 and by means of thin-sections and hand- 

 specimens : 



• Published by permission of Dr. J. M. Clarke, 

 New York State Geologist. 



