November 17, 1916] 



SCIENCE 



713 



tention. This is not a matter of lack of space; 

 it results from rigidly following a predeter- 

 mined plan, and ignoring everything which 

 does not fall within the artificially limited 

 scope of the enquiry. It was the same attitude 

 which caused Sir Geo. P. Hampson, in the 

 great catalogue of moths published by the 

 British Museum, to refuse to recognize or men- 

 tion the genitalic characters of the segregates 

 of Apamea nictitans, although the facts, ac- 

 companied by prepared slides, were freely 

 offered for his use. This extreme rigidity of 

 method has certain advantages; it permits 

 consistency of treatment, and allows the au- 

 thor to base the whole classification on char- 

 acters which he thoroughly understands and is 

 accustomed to use. It may also be urged with 

 reason that it is impossible to study or describe 

 all the structures of animals, and consequently 

 it is necessary to make a selection. Still 

 another argument may be based on the fact 

 which modern comparative morphology is daily 

 making more apparent, that the minute study 

 of almost any important structure in a long 

 series of species will afford a fairly sound basis 

 for classification. Thus Dr. Asa C. Chandler, 

 in his remarkable account of the microscopical 

 features of feathers, lately published by the 

 University of California, shows that if we pos- 

 sessed only feathers, the birds otherwise being 

 wholly unknown to us, we could construct 

 from them a rational classification of the class 

 Aves. Similarly, Dr. Edna Mosher, in a study 

 of the Lepidopterous pupa published this year 

 by the Illinois State Laboratory of Natural 

 History, is able to construct a classification of 

 moths and butterflies on the pupae alone. It is 

 noteworthy, however, that while the feathers 

 of birds and the pupse of moths essentially con- 

 firm existing systems of classification, they 

 afford some discordant facts, which at least sug- 

 gest the propriety of certain modifications. 

 Precisely the same thing is true of the scales 

 of fishes. The development of organs and 

 characters in animals does not present an even 

 front; evolution within the limits of the or- 

 ganism is unequal in degree and rapidity, and 

 hence each set of structures teaches some les- 

 sons which the others do not supply. No single 



worker, dealing with a large group, can take 

 the time to search for all these illuminating 

 footnotes to the book of nature. It is the work 

 of the comparative morphologist to uncover 

 them; and while the professional taxonomist 

 may properly express an opinion whether in 

 this or that case they are significant for his 

 purposes, he can not safely look the other way, 

 pretending that they do not exist. ' 



t. d. a. cockerell 

 University of Colorado 



J. L. Pagel's Einfuhrung in die Geschichte der 

 Medizin in 25 akademischen Vorlesungen. 

 Zweite Auflage. Durchgesehen, teilweise 

 umgearbeitet und auf den heutigen Stand 

 gebracht von Karl Sudhofp in Leipzig. 

 Berlin, 1915, in 8°. Verlag von S. Karger, 

 pp. i-xv-f- 1-616. 



Within the past twenty years there has been 

 developed, especially in Germany, an inter- 

 esting subject — the history of medicine. 

 There has been great progress in the develop- 

 ment of this subject in all of its phases and 

 much light has been thrown on many new lines 

 of intellectual endeavor. There are two jour- 

 nals which are devoted exclusively to the his- 

 tory of medicine and related subjects. These 

 are : " Archiv fur die GeschicMe der Medizin," 

 edited by Karl Sudhoff, in Leipzig, of which 

 eight volumes have appeared, and the " Zool- 

 ogische Annalen, Geschichte der Zoologie," 

 edited by Max Braun, 1905 to date, of which 

 likewise, eight volumes have appeared. 



The two men involved in the production of 

 the book the title of which is given above have 

 been largely concerned in the development of 

 the history of medicine, together with their 

 co-workers Puschmann, Neuburger, Toply, M. 

 Holl and others. It is an important event 

 when the editor of the "Archiv fur die Ge- 

 schichte der Medizin " issues a second edition 

 of Pagel's Einfuhrung. After a lapse of seven- 

 teen years this important work is issued in a 

 second edition, which is increased in scope and 

 brought down to date by Karl Sudhoff. The 

 work was first issued by Pagel in 1898 as 

 Part I. of a two-volume work; the second part 

 being : " Historisch-medicinische Bibliographic 



