abstracts: botany and technology 185 



The paper is concluded by tables of 700 analyses of water made during 

 the study. It is a source of definite detailed information regarding the 

 chemical composition of the surface waters of Illinois. R. B. Dole. 



BOTANY.— Inheritance of the "eye" in Vigna. W. J. Spillman. Amer- 

 ican Naturalist, 45: Sept. 1911. 



Certain races of the cowpea (Vigna unguiculata) have the seed coat 

 pigmented only in certain areas. In all such cases the pigmented area 

 includes the region about the hilum and is called the eye. It varies 

 widely in size and form. 



Genetic studies of these races has demonstrated that there arc two 

 genetically distinct types of eye, both recessive. When the two types 

 of eye are brought together in the same individual by proper cross- 

 breeding, the resulting form of eye is that of the common eyed races of 

 peas, in which there is a small pigmented area about the hilum. One 

 type, without the other, gives a pigmented area covering something 

 over half the surface of the seed ; the other type alone gives a pigmented 

 area about the hilum, the edges of the area being indistinct, fine dots 

 of pigment extending into the unpigmented area and covering the micro- 

 pilar end of the seed. 



It is shown that four different hypotheses regarding the nature of 

 the hereditary factors responsible for the eye are in accord with the 

 genetic behavior of the characters in question. W. J. S. 



« 



TECHNOLOGY. — The diffusion of crude petroleum through fidler's 

 earth, with notes on its geologic significance. J. Elliott Gilfin 

 and Oscar E. Bransky. Bulletin U. S. Geological Survey No. 

 475. Pp. 50. 1911. 



When a solution of benzene and a paraffin oil diffuses upward through 

 a tube packed with fuller's earth, the benzene collects below and the 

 paraffin oil above. When crude petroleum diffuses a fractionation 

 occurs. The oil from the top of the tube possesses a lower specific 

 gravity than that from the bottom. As the fractionation proceeds the 

 range of specific gravity covered becomes smaller, indicating the pro- 

 duction of mixtures which will finally pass through the earth unaltered. 

 The amounts of unsaturated hydrocarbons and sulphur compounds in 

 the fractions increase gradually from the lightest oils above to the heav- 

 ier oils below. 



Fuller's earth retains the unsaturated hydrocarbons and sulphur 

 compounds in petroleum, thus exercising a selective action upon the 

 oil, H. D. McCaskey. 



