212 



SCIENCE. 



[N. S. Vol. XX. No. 502. 



ests in the Lewis and Clarke reserve, the 

 glaciated valley, the numerous mountain 

 chains, the unknown animal and vegetable 

 life, suggest numerous topics for the 

 thoughtful student. 



There is no reason why eastern friends 

 shoiild not make the laboratory a ren- 

 dezvous during the summer. One can 

 recreate ' to the fullest and yet have a 

 definite object in view. It is impossible 

 to visit the mountains and see them with- 

 out some one of experience to help the 

 visitor around. Vacation is gone before 

 the wanderer 'hits the trail' he is seeking. 

 His inexperience leads him to undertake 

 things he can not do. Montana can not be 

 seen from the car window. One must push 

 out of the canyons. He is unwise who 

 enters the pathless forests alone. They 

 are too vast, the hills are on too large a 

 scale, and the difficulties are too great to 

 be entered hastily. 



From the laboratory the collector may 

 easily reach alpine heights, where grand 

 scenery is spread before him. He may 

 gather material for future study, under- 

 take serious study indoors, more serious 

 and more difficult study out of doors, and 

 have the help and wisdom of those who 

 have spent years in wandering in search 

 of such places as many wish to visit and 

 such specimens as many would gladly 

 gather. The building is entirely inade- 

 quate to the demands of those attending, 

 but it is believed that when the merits of 

 the station are known and its opportunities 

 fairly presented it will not lack for suitable 

 quarters. 



The summer session opened on July 18, 

 and continues five weeks. The illustrated 

 pamphlet, giving full information, will be 

 sent to any one requesting it. 



Morton J. Blrod. 

 UNrvERsiTy OF Montana, 

 Missoula, Mont. 



SCIENTIFIC BOOKS. 



The Evolution of Earth Structure with a 



Theory of Geomorphic Changes. By T. 



Mellaed Reade. New York, Longmans, 



Green & Co. 1903. 



This work may be considered as a sequel to 

 the well-known volume entitled ' The Origin 

 of Mountain Ranges,' by the same author, 

 which appeared in 1886. It is divided into 

 three parts. The first of these treats of ' Geo- 

 morphic Changes ' and deals with Regional 

 Oscillation, the Relation of Continental Evo- 

 lution to Mountain Building, Continental 

 Growth and the Sub-Oceanic Configuration of 

 the Earth's Crust.. The second part deals 

 with the ' Dynamics of Mountain Structure ' 

 and the experimental elucidation of the same, 

 while the third part is made up chiefly of re- 

 prints of papers by the author on subjects 

 allied to those just mentioned, which papers 

 have appeared at various times and in different 

 journals. 



The aiithor first cites numerous cases where 

 there is distinct evidence of changes of level 

 in the earth's crust, with concomitant bending 

 of the strata composing the crust. He con- 

 siders the principle of isostacy as quite inade- 

 quate to the explanation of these movements, 

 since the mass of the solid earth involved 

 in upward movement is entirely too great to 

 be explained by any sedimentation which has 

 taken place in the same period of time. These 

 changes of level the author believes must be 

 due to change in bulk of certain sections or 

 portions of the earth's crust, without change 

 of mass; the irregularities in the earth's sur- 

 face, in fact, arising from differences in the 

 specific gravities of the earth's crust and the 

 underlying matter. These specific gravities 

 are not stable, but are subject to slow changes 

 consequent upon changes of temperature. A 

 rise in temperature and increase in volume 

 create a protuberance; a fall in temperature, 

 on the other hand, gives rise to a depression, 

 even to one of those profound abysses of the 

 ocean aptly named ' deeps.' The cause of 

 these secular variations in temperature, how- 

 ever, is not set forth, although in the mind of 

 the author it seems to be in some way con- 

 nected with chemical changes taking place in 



