June 11, 1909] 



SCIENCE 



939 



childhood, if the individual has been favored 

 by fortune, he exercises and develops more or 

 less extensively the primitive instincts and 

 modes of the race in a free out-door life, and 

 the result is so much mind-stuff to be dissolved 

 and transformed with more or less coercion 

 and under more or less constraint into a mind 

 of the twentieth-century type. The period 

 during which a young man is receiving his 

 scientific and professional training is indeed 

 analogous in many respects to the period of 

 complete reorganization of bodily structure, 

 and in the other we have a reorganization no 

 less complete of mental structure; in the one 

 the reorganization is wholly dependent upon 

 and determined by internal energies, but in 

 the other the reorganization is largely de- 

 pendent upon and determined by esternal 

 constraint. 



It is a remarkable thing this changing of 

 men into bees and butterflies ! and the opera- 

 tion is indeed severe. But perhaps the most 

 remarkable thing about it is that it is elective 

 in particular, but apparently in our day a dire 

 necessity in general, somewhat like the curious 

 transformation of the axolotl, which lives al- 

 ways and reproduces his kind as a tadpole 

 unless a stress of dry weather annihilates his 

 watery world when he lops off his tasseled 

 gills, develops a pair of lungs and embarks on 

 a new mode of life on land. 



A severe operation! And usually for the 

 individual a change, like that of the axolotl, 

 from a fluid world to a rigid one! I remem- 

 ber as a boy a sharp contest in my own mind 

 between an extremely vivid sense of things 

 physical and the constraining function of pre- 

 cise ideas. This contest is perennial, but it 

 is not by any means a one-sided contest be- 

 tween mere crudity and refinement, for refine- 

 ment ignores many things. Indeed precise 

 ideas not only help to form our sense of the 

 world in which we live, but they tend to in- 

 hibit sense as well, and a world in which their 

 rule is unchallenged becomes indeed a dry and 

 rigid world. 



Every student should realize two things in 

 connection with his science study; the first is 

 that the study of the physical sciences is 

 exacting beyond all compromise, involving as 



it does a degree of coercion and constraint 

 which it is beyond the power of any teacher 

 greatly to mitigate; and the second is that 

 the completest science stands abashed before 

 the infinitely complicated and fiuid array of 

 phenomena of the material world, except only 

 in the assurance which its method gives. And 

 both of these things are obscured by books like 

 " Scientific Ideas of To-day," books that know 

 nothing of exacting constraint nor ever stand 

 abashed. The attempt to set forth in an easily 

 plausible style the conceptual structure of 

 modern physical science is one of the most 

 troublesome perversions with which one has 

 to deal in the attempt to contribute towards 

 the solution of what is to be perhaps the great- 

 est problem of the twentieth century, namely, 

 the making available to all nten of the simpler 

 phases of the logical structure of the sciences 

 in order to give to all men some measure of 

 that clear insight into nature which contrib- 

 utes so greatly to the ordering of one's daily 

 life. 



W. S. Franklin 

 Lehigh Univeesity 



Normentafel zur ErdwicMungsgescMcMe des 

 Menschen. By Franz Keibel and Curt 

 Elze. 4to, 314 pp., 6 pis., and numerous 

 text figs. Jena, Gustav Fischer. 1908. 

 This eighth volume in Professor Keibel's 

 series of " Normentafeln " is much larger than 

 any of its predecessors, thus reflecting the 

 special interest which mankind takes in hu- 

 man embryology. Like the earlier numbers 

 it consists essentially of a tabular description 

 of embryos, with plates showing their ex- 

 ternal form, and a classifled bibliography. 

 The titles of papers relating to human embry- 

 ology occupy 150 quarto pages, and yet, of the 

 publications dealing with malformations, only 

 the more comprehensive have been included. 

 The bibliography is so thorough and useful 

 that it renders this " Normentafel " indispen- 

 sable to every student of vertebrate embry- 

 ology. The plates are excellent, and show 

 embryos from 1.17 to 24 mm. in length, seen 

 in several positions. The text figures include 

 numerous single sections, and several partial 

 reconstructions of the embryos described. A 



