846 



SCIENCE 



[N. S. Vol. XXXIV. No. 885 



nature, if it ever occurs, and physiographers 

 have done well (and physicists would do well) 

 to omit it from their text-books. But in a 

 modified form the siphon is probably occasion- 

 ally operative. A figure which, although im- 

 perfect, is more in accord with the structure 

 of limestone strata and the effect of solution 

 upon them is given by de Martonne (" Traite 

 de Geographic Physique," 1909, p. 347, fig. 



1474). In this case (Fig. 1) the joints of the 

 rock are shown to be widened by solution in 

 such a manner as to make a siphon spring 

 (s) possible. On the left a normal siphon is 

 shown in which the spring does not flow until 

 the reservoir ABCD is filled to B, that is, 

 until the water begins to flow through the long 

 arm EF of the siphon. On the right of the 

 valley is an inverted siphon. It is perhaps 

 unnecessary to state that although intermit- 

 tent springs are the commonest of all springs 

 the intermittent character seldom depends 

 upon the presence of a siphon. 



Sink Holes. — Sink or swallow holes are 

 formed in one of two ways: (1) by the falling 

 in of the roof of a cavern and (2) by the 

 solution and erosion of the rock along joint or 

 fault planes, the latter being by far the com- 

 moner origin. American writers of text-books 

 of geology and physiography usually give but 

 one explanation of the origin of these features 

 and that the first and most unusual. Only 

 two authors, as far as the writer is aware, give 

 both. The popularity of the first explanation 

 is probably due to the fact that the word 

 " sink " implies a sinking in of the surface as 

 well as the disappearance of the water by pour- 

 ing into a funnel. The suggestion is offered 

 that the older (?) term "swallow" hole be 

 used, since it carries with it only the thought 



of the disappearance of the water in a throat 

 or funnel. Herdman F. Cleland 



WiLLIAMSTOWN, MASS., 



November 3, 1911 

 THE ROLE OF SALTS IN THE PRESERVATION OF LIFE 



In my address on " The Eole of Salts in the 

 Preservation of Life," published in No. 381 of 

 Science, I made the following statement " Sev- 

 eral authors, Lillie, McClendon and Lyon, 

 have suggested that the fertilized egg is more 

 permeable to salts than the unfertilized egg." 

 Mr. E. Lillie calls my attention to the fact 

 that he never made this suggestion. I feel it 

 my duty not only to express my regrets for 

 my oversight but to add that if my paper had 

 dealt fully with the literature of the subject 

 Mr. Lillie's ingenious experiments and orig- 

 inal ideas should have occupied a prominent 

 place in it, as those who are familiar with the 

 subject will fully realize. 



Jacques Loeb 



SCIENTIFIC BOOKS 

 Oiservaiions and Investigations made at the 

 Blue Hill Oiservatory, Massachusetts, 

 U. S. A., in the Years 1906, 1907 and 1908, 

 under the Direction of A. Lawrence Eotch. 

 Annals of the Astronomical Observatory of 

 Harvard College. Vol. LXVIIL, Part II., 

 4to. Cambridge, Mass. 1911. Pp. 99-229, 

 Figs. 15. 



The work of the Blue Hill Observatory 

 needs no introduction to the readers of 

 Science. The progress of that unique insti- 

 tution, so important for American meteorol- 

 ogy, has been faithfully recorded in the col- 

 umns of this journal ever since the founda- 

 tion of the observatory in 1884. Meteorol- 

 ogists have long since learned that the Blue 

 Hill volumes of the Annals of the Harvard 

 College Observatory are sure to contain re- 

 sults worthy of careful note and study. 



Volume LXVIIL, Part II., of these Annals 

 contains the observations made twice daily in 

 1906-08; the usual summaries; results from 

 the kite meteorograph and simultaneous rec- 

 ords at the ground 1906-08; data obtained by 

 means of hallons-sondes at Pittsfield, Mass., 

 in 1908; supplementary data for a manned 



