38 



SCIENCE 



[N. S. Vol. XXXIII. No. 836 



feet above the top of the pipe entering the 

 well the spouting should cease, since the pipe 

 will then be carrying water at its full ca- 

 pacity with little or no air under these con- 

 ditions entering the well. As a matter of 

 fact following the heavy rains attending the 

 storm of October 17 and 18, 1910, the lake 

 rose several feet and the well upon being re- 

 opened received water without spouting. A 

 similar spouting well at Albany, Ga., was de- 

 scribed some years ago by Professor S. W. 

 McOallie.' 



E. H. Sellards 

 Tallahassee, Fla. 



graphite in vein quartz' 

 The writer has recently discovered a gra- 

 phitic quartz in Troup County, 6a., which has 

 some geological significance, since it is en- 

 tirely unlikely that the graphite is directly of 

 organic origin. The graphite occurs in mas- 

 sive vein quartz and, recognizing the already 

 known occurrence of graphite in pegmatite 

 and gneiss at other localities, affords addi- 

 tional evidence of the inorganic origin of 

 graphite under peculiar geological conditions. 

 The graphite occurs in small flakes and in 

 irregular bunches, two or three millimeters in 

 diameter or length, disseminated through 

 massive, clear quartz. In fact, in the speci- 

 mens at hand, except for iron stains, quartz 

 and graphite are the only components of the 

 rock. Under the microscope, minute black 

 crystals were noted, but the black color disap- 

 peared upon ignition, leaving the crystal form 

 intact, indicating only a covering of graphite 

 over minute quartz crystals. The graphite, 

 roughly estimated, forms only two or three 

 per cent, of the quartz at present exposed. 



The nearest rock exposed in the vicinity of 

 the quartz vein is a peridotite and it is not 

 improbable that the vein is cutting this rock. 

 The quartz, of course, could possibly be de- 

 rived from pegmatite, but at the surface 

 neither feldspar nor mica were found with it. 

 The vein is evidently of small dimensions. 



^Science, N. S., XXIV., p. 694, 1906. 

 ^ Published with the permission of the state 

 geologist of Georgia. 



The nearest strata of certain sedimentary 

 origin are the Pine Mountain quartzites a 

 few miles to the southward. 



Whether the quartz was deposited from an 

 aqueous solution or is of aqueo-igneous origin, 

 the carbon must have been held in some form 

 in the rock solution and the graphite de- 

 posited contemporaneously with the quartz. 

 Its dissemination, not cavity filling, through 

 compact, crystalline quartz is sufiicient evi- 

 dence that it is not directly of organic origin 

 or derived from the metamorphism of car- 

 bonaceous matter. Perhaps the most sugges- 

 tive theory of the origin of the graphite under 

 these conditions is that it was derived from 

 carbon dioxide (C0„), or a hydrocarbon vapor 

 held in the siliceous solution. The presence 

 of carbon dioxide in crystals of quartz is well 

 known. Smoky quartz from Branchville, 

 Conn., yielded gas, analyzed by A. W. 

 Wright, which contained 98.33 per cent, of 

 CO,. 



Otto Veatch 



/ 



CONCERNING SEXUAL COLORATION 



In the linnet of California (Carpodacus 

 frontalis), after the post-juvenal (first fall) 

 molt, the sexes are conspicuously different in 

 color. The female is obscurely streaked be- 

 neath with hair-brown on a dull white ground, 

 above more uniformly hair-brovra. The male 

 is usually red in color, on the whole chin, 

 throat, malar region and chest, on the frontal 

 and lateral portions of crown, and on the 

 rump; otherwise the male is like the female. 

 The linnet would thus appear to provide a 

 good case of " sexual coloration." 



After the post-juvenal molt, there is, in 

 both sexes throughout the lifetime of the in- 

 dividual, but one molt annually, taking place 

 in August. There is no pre-nuptial molt. 



In a large series of male linnets, leaving out 

 the occasional aberrant examples which are 

 distinctly yellow or orange, striking variation 

 is shown in the shade and intensity of the red. 

 Arrangement of the component examples by 

 date, from September to July, shows this 

 variation to parallel uniformly the lapse of 

 time beyond the annual molt in August. In 



