March 20, 1903.] 



SCIENCE. 



467 



3Y pages. All the old, threadbare opinions 

 and speculations that have formed the staple 

 of embryological literature for the last twenty- 

 five years are tediously passed in review — only 

 once more to reject the gastrula theory, a 

 conclusion already reached by so many writers 

 that it would be tiresome merely to cite their 

 names. 



The germ-layer definition is ' analyzed,' by 

 which is meant more empty surmising. Fi- 

 nally the reader, if he has not long since 

 lost interest in the protracted discussion, is 

 rewarded by a sort of diversion on ' physio- 

 logical morphology,' where more commonplace 

 and vacuity are in order. 



When morphologists, on the slender basis 

 of a few, new, trivial histological details, can 

 trespass on the time of their fellow-workers 

 to the extent of 174 quarto pages of anti- 

 quated discussion, it is, indeed, time to fly 

 f 3?om such company and seek new fields where 

 the length .of a contribution may be expected 

 to bear some relation to the importance of 

 the discoveries. T. H. M. 



Biological Laboratory Methods. By P. H. 



Mell. Pp. xii + 321. JSTew York, The 



Macmillan Co. 1902. 



It is difficult in a brief statement to do 

 justice to the work of Dr. Mell. We may, 

 however, find the task simplified when we 

 realize that a very considerable amount of 

 the space is devoted to the 127 figures, many 

 of large size, almost all of which are taken 

 from the catalogues of dealers in laboratory 

 and microscopic supplies, and in other appa- 

 ratus more or less pertinent to the needs of 

 the biologist. Indeed, the addition of an 

 appendix containing a list of prices would 

 have rendered the publication of catalogues 

 by these dealers for some time hereafter a 

 work of gratuity. 



For the rest of the book — say sixty per cent. 

 — it may be said to contain a detailed account 

 of a large number of photographic and micro- 

 scopic apparatus and methods for most of 

 which the beginner in biology — ^for whom the 

 work is intended as a text-book in a strict 

 sense — will scarcely have use. The same 

 may be said of the very numerous directions 

 for the preparation of tissues. It is remark- 



able in such a text-book, the rationale of 

 which is to enable the beginner to ' build only 

 the foundation ' of biological study, that the 

 for him more simple and useful methods of 

 making simple microscopic preparations of 

 fresh tissues are chiefiy omitted. But, of 

 course, we are rapidly passing beyond the 

 pitiable simplicity of ante-microtomic days. 

 The young student of nowadays will, with 

 Dr. Mell's book, get an elaborate knowledge 

 of chromatic aberration and numerical aper- 

 tures. He will then devote himself to a care- 

 ful and somewhat exhaustive study of micro- 

 tomes, following which he will address him- 

 self to the numerous special methods of kill- 

 ing, hardening, clearing, imbedding and the 

 like, and of photography, bacteriological 

 methods, injection, maceration and polariza- 

 tion in the order named. The student, having 

 mastered these things, will then presumably 

 be ready for the study of biology in the nar- 

 rower sense, that, namely, of plants and ani- 

 mals themselves. F. E. Lloyd. 



Oeuvres Completes de J.-O. Galissard de 

 Marignac; Hors-serie des Memoires de la 

 Societe de Physique et d'Histoire Naturelle 

 de Geneve. Geneva, Ch. Eggiman et Cie; 

 Paris, Masson et Cie, et al. Vol. II. 4to. 

 Pp. 840. 



This volume completes the admirably exe- 

 cuted reprint of the researches of the great 

 Swiss chemist, the first volume of which was 

 reviewed by Science on January 16, 1903 

 (p. 111). The final volume contains Marig- 

 nac's most important memoirs on atomic 

 weights, a number of interesting and clear- 

 sighted papers concerning various rare ele- 

 ments, several critiques and many papers upon 

 physico-chemical subjects, including his im- 

 portant researches on the specific heats of 

 solutions. At the end is a list of the atomic 

 weights determined by Marignac, in parallel 

 column with the ' International ' values of 

 1903 — a comparison which redounds greatly 

 to Marignac's credit. A classified index cov- 

 ering both volumes completes the collection, 

 leaving nothing to be desired. The editor, 

 M. E. Ador, is much to be congratulated on 

 the success of his work. 



Theodore William Eichards. 



