760 



SCIENCE. 



[N. S. Vol. XVIII. No. 467. 



witli quartz sand. While not yet completed, 

 this investigation has already shown that a 

 rich adobe (clay) soil, as well as an equally 

 rich sandy soil, diluted to an extent of four 

 to one, shows equally good growth, but that 

 when in these soils the dilution reaches five 

 to one, development is ^quite slow, and in a 

 short season would mean a crop failure. The 

 moisture content was in all these cases main- 

 tained at one half the maximum water ca- 

 pacity of each diluted soil. Photographs show 

 clearly that here the roots made up by their 

 extension for the lack of concentration of 

 the food supply; hut at the dilution of one 

 to five they were unable to make up that de- 

 ficiency, at least within a reasonable time, al- 

 though the same total amount of food ingredi- 

 ents was always present in the increased bulk. 

 Other things being equal, it is the proportion, 

 then, between the several soil ingredients, 

 quite as much as the absolute quantity at hand, 

 that determines production. Incidentally, 

 this experiment shows the wide variation of 

 physical composition (from a soil containing 

 35 per cent, of colloidal clay to one with only 

 8.75 per cent., and in the sandy soil from 7.6 

 per cent, to 1.9 per cent.) within which plants 

 will do equally well, provided the plant food 

 ingredients are rightly proportioned; and pro- 

 vided also that a proportionally large soil mass 

 is available to each plant. 



In the foregoing discussion, only the salient 

 points of the bulletin in question have been 

 taken up, and their most obvious weaknesses 

 briefly considered. To do more would involve 

 the writing of a paper as long as the bulletin 

 itself; and it is to be hoped that the matter 

 will be taken up by others, also. Thus, for 

 instance, the Eothanistead Station might have 

 something to say regarding the singular in- 

 terpretation here put upon the splendid work 

 of Lawes and Gilbert. 



In conclusion, it seems to the writer that 

 the verdict upon the main theses put forward 

 so confidently in this paper must be an em- 

 phatic ' Not proven ! ' 



E. W. HlLGAED. 



Berkeley, CALn?0ENiA, 

 November II, 1903. 



ABSORBED GASES AND VULCANISM. 



To THE Editor of Science : The descriptions 

 of the spine of Mont Pele by Hovey and Heil- 

 prin remind me of the phenomenon I observed 

 some ten years ago, when my mind was on the 

 subject of the part which the original absorbed 

 gases play in vuleanism, as discussed in my 

 paper in the Bulletin of the Geol. Soc. Am., 

 March 3, 1894. I had a bottle of Werner's 

 grape milk packed in the place of the tin of 

 an ice cream freezer, the same having served 

 its purpose, in order to cool it. I presume 

 any other carbonated beverage would work 

 similarly. Though chilled well below 0° C. 

 the beverage remained clear and unfrozen, as 

 long as it was corked, but upon removing the 

 cork the gas began to escape and freezing to 

 set in rapidly. Sometimes nearly the whole 

 contents of the bottle would freeze. Upon 

 one occasion, however, I remember seeing a 

 ' volcanic plug' of frozen matter forced out in 

 a round cylinder from the neck. 



I am inclined to think that there may be a 

 very close analogy with the Mont Pele spine. 

 I think it would not be very difficult to repro- 

 duce this phenomenon, though I can not tell 

 the exact temperature at which it occurred. 

 Alfred C. Lane. 



SHORTER ARTICLES. 

 THE heredity OF ' ANGORA ' COAT IN JIAMMALS. 



That Mendel's law is a fundamental prin- 

 ciple of heredity becomes daily clearer as new 

 illustrations of its workings come to light, 

 either through a reexamination of the older 

 observations on heredity or through the per- 

 formance of new experiments. One of these 

 new illustrations it is the purpose of this note 

 briefly to describe. 



The writer has already pointed out, in the 

 columns of Science, two pairs of alternative, 

 or Mendelian, characters pertaining to the 

 hairy coat of guinea-pigs. (1) A pigmented 

 coat of any sort is dominant over an unpig- 

 mented, or albino, coat. Accordingly when 

 a pure-bred pigmented guinea-pig is mated to 

 an albino, the young are invariably pigmented. 

 (2) The rough, or ' resetted,' condition of 

 coat found in so-oajled Abyssinian and Peru- 



