896 



SCIENCE 



[N. S. Vol. XXIX. No. 752 



of adaptations out of the natural selection of 

 undirected variations, to use my colleague's 

 language, may prove to be a dogma quite as 

 unsupported by facts as the Lamarckian dogma 

 of the inheritance of acquired characters. 

 I long ago pointed out that a very large 

 number of new characters in the hard parts 

 of mammals are adaptive in direction from 

 the beginning; I am very far from saying that 

 all new characters are adaptive in direction; 

 I only make this statement as to those char- 

 acters I have had the opportunity of repeat- 

 edly observing. 



I now challenge the zoologists to produce a 

 single instance of a series of animals in which 

 adaptive characters are being accumulated 

 through the selection of undirected variations, 

 i. e., of variations which are thoroughly mixed 

 up, in which there is no law evident. Such a 

 series has never been produced by any one. 

 Of course I bar from this challenge orthogenic 

 changes of character under environmental in- 

 fluences. I refer to the pure Darwinian hy- 

 pothesis. The hypothesis is still as Darwin 

 left it, an ingenious working theory, awaiting 

 either experimental evidence or evidence of 

 any kind. How long this assumption will pass 

 muster as based on observation it is hard to 

 say. We await some paleontological Weis- 

 mann who will smite it hip and thigh as the 

 zoological Weismann smote Lamarck's as- 

 sumption. 



While the " philosophic zoologist " of to-day 

 has made his choice, the philosophic paleon- 

 tologist has also made his choice. The latter 

 certainly does not find direction in the old 

 teleologic sense, but quite as certainly he finds 

 no evidence of such fortuity as will justify the 

 use of the word undirected as furnishing ma- 

 terials for natural selection. The materials 

 for natural selection are furnished by the 

 ensemble of an enormous number of charac- 

 ters, each of which is a unit pursuing its inde- 

 pendent history and fluctuating and mutating 

 and moving in direct lines under laws which 

 the philosophic paleontologist has proof of, 

 but totally fails to understand. Consequently 

 he assumes the agnostic position that there is 

 some principle, or principles of direction, or 

 better — to use Professor Morgan's own words 



— "unlvnown agencies," still to be discovered 

 other than the principle of order coming out 

 of fortuity. 



Henry Fairfield Osborn 



js'elson's loose leaf encyclopedia. 



To THE Editor of Science: In February 

 an article was published in Nelson's "Loose 

 Leaf Encyclopedia" upon the Messina-Eeggio 

 earthquake, the authorship of which was 

 credited to Mr. Frank A. Perret and myself. 

 In justice to Mr. Perret, however, it should 

 be stated that he had nothing whatever to do 

 with the preparation of the article beyond 

 furnishing the one item pertaining to the 

 height of the " tidal " wave at Messina which 

 is duly credited to him. The insertion of Mr. 

 Ferret's name as joint author was done by the 

 publishers of the encyclopedia without my 

 knowledge or consent, but thus far I have 

 been imable to obtain any correction of their 

 error. E. O. Hovey 



New Yoek, 

 May 11, 1909 



SGIENTIFW BOOKS 

 General Physics. By Henry Crew. New 



York, The Macmillan Co. 1908. 

 A Text-hooh of Physics. Edited by A. Wil- 



MER Duff. Philadelphia, P. Blakiston's 



Son & Co. 1908. 



The publication of these two excellent text- 

 books designed for college classes in physics 

 illustrates the general dissatisfaction among 

 college professors of physics with both exist- 

 ing text-books and accepted methods. There 

 are many difiiculties inherent in the teaching 

 of physics and there are many points concern- 

 ing which the best teachers are to a certain 

 degree undecided. As physics is taught at 

 the present time in most American colleges 

 the time devoted to it is one year during each 

 week of which there are three hours of lectures 

 or class work, accompanied by five or six hours 

 of laboratory work. In this time a student 

 is supposed to cover the field of elementary 

 mechanics, properties of matter and physics 

 proper, including heat, light, etc. Within 

 recent years a demand has arisen for text- 

 books which should have more or less refer- 



