May 4, 1906.] 



SCIENCE. 



691 



possible by several men, and the subject 

 lias been given a certain amount of atten- 

 tion by nearly all recent students of 

 zoophytes. We are obtaining more in- 

 formation on the physical determinants in 

 the distribution of these organisms, but 

 no one will be able to furnish more than 

 an hypothetical explanation of the facts 

 now accumulating until the conclusions are 

 tested by experiments. Corals that grow 

 in shallow water are fortunately easily ex- 

 perimented with, and I have hoped that 

 the oiScials of the Carnegie Institution 

 might undertake some work with them. 

 Dr. C. Montague Cooke, of Honolulu, has 

 told me that he intends undertaking a 

 series of experiments on the reefs on the 

 south coast of the Island of Molokai. 

 Probably within a few years it will be 

 possible to present definite data from the 

 Madrepora on the questions now espe- 

 cially under consideration. 



T. Wayland Vaughan. 



SCIENTIFIC BOOKS. 

 Les tremhlements de terre. Par F. de Mon- 



TESSUS DE Balloee. Paris, Libraire Ar- 



mand Colin. 



In Vol. IV., 1900, of Beitrdge fur Geo- 

 physik. Major de Montessus published a 

 tabular statement of the seismicity of the 

 various portions of the earth, divided into 

 provinces. In the computation, 131,922 earth- 

 quakes were used and 10,499 epicenters; num- 

 bers far exceeding what had been compiled by 

 preceding systematists taken all together. It 

 was the work of many years, and from the 

 mass of evidence distributively grouped he 

 drew certain important conclusions. They 

 were briefly as follows : (1) In a group of 

 adjacent seismic regions, the most unstable 

 (i. e., most affected by quakes) are those 

 which present the greatest differences of 

 topographic relief. (2) The unstable regions 

 are associated with the great lines of corruga- 

 tion of the terrestrial crust. (3) Rapidly 

 deepening littorals, especially if they border 



important mountain ranges, are unstable, 

 while gently sloping littorals are stable, es- 

 pecially if they are the continuations of flat 

 or slightly accidented coastal plains. (4) 

 Though it is possible to indicate regions 

 which present both volcanoes and earthquakes, 

 there is no proof of interdependence between 

 seismicity and volcanicity in general. While 

 there are earthquakes which are certainly of 

 volcanic origin, the one phenomenon does not 

 necessarily imply the other. These views have 

 been borne out and have been generally adopted 

 by seismologists in the period of six years 

 since they were promulgated. 



But de Montessus seems to have been un- 

 willing to let the matter rest. The inferences 

 he drew in 1900, indeed, have not been 

 abandoned. They, however, express the rela- 

 tions of seismicity to topography, and not to 

 the causes of earthquakes, which were the real 

 objects of his grand research. He has, there- 

 fore, taken up the subject anew, rearranged 

 his facts, added to their number and made new 

 generalizations from a geological as well as a 

 topographical standpoint. And the new gen- 

 eralizations are of even greater interest and 

 more striking than those of 1900. These are 

 set forth briefly in the introductory chapter 

 of the publication before us. 



According to this analysis, earthquakes oc- 

 cur about equally, and almost exclusively, in 

 two great circles or zones, which make with 

 each other an angle of 67°. These zones are 

 (1) the Mediterranean, or Alpine-Caucasian- 

 Himalayan, which includes 52.57 per cent, of 

 the quakes, and (2) the circum-Pacific Andean- 

 Japanese-Malayan, which includes 38.51 per 

 cent, of the quakes. These two zones coincide 

 with the two most important lines of relief 

 of the earth's surface. The poles of these 

 great circles are situated 45° 45' N., 150° 30' 

 W., and 35° 40' N., 23° 10' E., respectively. 



This relation, which so far is purely 

 geometric, calls for a geological interpretation, 

 which may be read at once on the geological 

 map of the world. The zones which include 

 the seismic regions coincide exactly with the 

 geosynclinals of the mesozoic age as they are 

 figured by Haug in his well-known memoir, 

 ' The Geosynclinals and the Continental 



