February 14, 1919] 



SCIENCE 



171 



Ilistonj and Method of Science. The first 

 volume of this work was issued by the Oxford 

 University Press in 1917. I understand that 

 the second volume is now ready for the press 

 and Dr. Singer tells me that he hopes to share 

 with me the editorial responsibilities of the 

 third and succeeding volumes. Thus, Isis and 

 the Stiidies would be supplementary one to the 

 other, and between them would provide suitable 

 outlet for new work on the history and phi- 

 losophy of science. 



George Sartox 

 Cabneqie Institution op Washington 



a steady calendar 



To THE Editor of Science : The interruption 

 of our recent scientific meetings by the coming 

 of Sunday in the middle of the (Christmas) 

 week — a reputed impossibility that happens 

 every five or six years — is one of the many 

 inconveniences that we half-consciously en- 

 dure as the result of inheriting a varying 

 calendar from the unscientific past. If 

 in adopting any one of the many improved 

 calendars that have been proposed, we should 

 annually sacrifice upon the altar of reason a 

 single day in ordinary years and two days in 

 leap years, as extra days without week-day 

 names, then Christmas and New Years would 

 always fall on the same day of the week; 

 and by waiting to begin the sacrifice until those 

 holidays come on a Saturday or a Monday, the 

 scientific meetings of the last five days of the 

 year, which have become so well established 

 among us, would never thereafter be broken in 

 half by an interrupting Sunday. Home cele- 

 brations and scientific meetings would both 

 profit by the change. How can we best bring 

 it about? 



W. M. Da\is 



CAMBRioaE, Mass., 

 January 4, 1919 



SCIENTIFIC BOOKS 



Forced Movements, Tropisms and Animal 

 Conduct. By J. Loeb. Philadelphia. 1918. 

 Pp. 209, 42 figs. 

 The scope and character of this volume are 



in large part explained by the fact that it is 



offcro<l as one of a series of monographs in 

 which it is proposed to cover the field of re- 

 cent developments in biology. The announced 

 titles of the volumes scheduled to follow this 

 first number deal, not so much with rational 

 divisions of the science, as with those partic- 

 ular phases of physiology that have been the 

 subjects of investigation at the hands of the 

 respective writers. This general plan, already 

 justified by its success in the treatment of 

 modern advances in physical and biological 

 chemistry, and in human physiology, necessar- 

 ily results in a less closely coordinated system 

 of monographs when applied to physiology 

 proper — the latest of the sciences to acquire a 

 realization of the analytical significance of 

 quantitative methods of thought. 



The first volume of the proposed series, then, 

 endeavors to present within the space of some 

 170 pages a concise statement of the theory of 

 tropisms, their origin in forced movements 

 under various forms of aotivation, and their 

 importance for the analysis of animal con- 

 duct, including that of Homo. Much of the 

 matter discussed is, of course, no longer new; 

 about half the content of the book is already 

 familiar from the author's similar' article in 

 Winterstein's " Handbuch," and other publica- 

 tions; but as a compact, clear, and character- 

 istically vigorous statement of the essential 

 quantitative data upon which the tropism doc- 

 trine now rests, the book is welcome and in the 

 main satisfying. In the introductory section 

 it is pointed out that tropistic phenomena, de- 

 pending upon the orientations of the animal 

 as a whole, rather than the segmental re- 

 flexes, must be made the starting point for the 

 analysis of conduct; that these tropistic orien- 

 tations must first be studied in the behavior of 

 bilateral animals; and that the key to the 

 understanding of tropisms lies in forced move- 

 ments initiated through differential tensions 

 in symmetrical contractile elements of the 

 body, not in the distinction of "pleasure" 

 from " pain." It is only on such a basis, so 

 far as we know, that quantitative laws may be 

 deduced adequate for the description of be- 

 havior. This procedure is illustrated partic- 



