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March 30, 1900] 



SGIENGE. 



505 



tO' be desired (e. g., Fig. 122). Tlie new illus- 

 trations are largely from Government reports, 

 but many photographs are by individuals, es- 

 pecially by the author. From these it appears 

 that, since the publication of the iirst edition, 

 the author has himself visited some of the im- 

 portant mining districts of the west, but in 

 many cases it is evident he still does not possess 

 sufficient familiarity with the regions to judge, 

 from published reports of a given mining dis- 

 trict, whether or not those of one author pos- 

 sess inherent merits entitling his views to 

 superior consideration over those of another. 



Professor Kemp, who is an excellent petrog- 

 rapher, has, as shown by his papers published 

 elsewhere, a decided leaning toward the theory 

 of magmatic separation of ore minerals held by 

 Scandinavian geologists, like them, viewing the 

 subject primarily from a petrographic stand- 

 point. The sufficiency of this method for the 

 formation of ore deposits, unless aided by later 

 concentrations through the agency of circulating 

 waters, is not, however, regarded with so much 

 favor by most mining geologists of wide prac- 

 tical experience in America. 



Taken as a whole the book presents an excel- 

 lent bird's-eye view of the ore deposits of the 

 -country, as nearly up to date as is practicable, 

 with a fair-minded presentation of the various 

 views held as to their origin and mode of forma- 

 tion. The mining community is certainly in- 

 debted to Professor Kemp for the ability and 

 thoroughness with which he has accomplished 

 his laborious task, the magnitude of which few 

 beside the author can adequately appreciate. 

 S. F. Emmons. 



The Nature and Work of Plants. An Introduc- 

 tion to the Study of Botany. By Daniel 

 Trembly MacDougal, Ph.D., Director of 

 the Laboratories, New York Botanical Gar- 

 den. New York, The Macmillan Company. 

 1900. Pp. xviii + 218. 12mo. 

 The author's introductory paragraph gives 

 us his point of view. " The course outlined in 

 this little book is essentially a study of the 

 functions or action of the plant, and organs are 

 considered chiefly as instruments for the per- 

 formance of work, with but little attention to 

 their morphology. It is believed that this 



method of introduction to the subject of botany 

 will be best suited for beginners who have not 

 at hand the facilities of a laboratory. In con- 

 formity with this idea, the use of technical 

 terms has been restricted to the actual necessi- 

 ties of logical treatment, and the demonstra- 

 tions have been developed by the simplest ex- 

 perimental methods." 



He takes up the subject in ten chapters, as 

 follows : I. the composition and purposes of 

 plants: II. the material of which plants are 

 made up; III. the manner in which different 

 kinds of work are divided among the members 

 of the body ; IV. the roots ; V. the leaves ; 

 VI. stems ; VII. the way in which new plants 

 arise ; VIII. seeds and fruits ; IX. the power 

 or energy of the plant ; X. relations of plants to 

 each other, and the place in which they live- 

 These chapters include two hundred and fifty 

 paragraphs, each of which directs attention to 

 a single fact or group of facts, which in most 

 cases maybe subjected to observation or experi- 

 ment by the pupil. Very simple suggestions 

 are given for these observations and experi- 

 ments, and the pupil is usually left quite free 

 to use his own ingenuity in carrying them out. 

 While function is emphasized, structure is not 

 ignored, but this is almost entirely confined to 

 gross structure, the author's intention being to 

 require no greater aid to the naked eye than a 

 hand lens magnifying from six to ten diam- 

 eters. 



The book is non-technical, in conformity to 

 the trend of recent text-books, and is remark- 

 able in having no illustrations whatever, the 

 author depending upon the simplicity and 

 clearness of his text and the plant or experi- 

 ment itself to furnish ideas to the pupil. 

 Whether the pupils and teachers who have been 

 brought to expect fine 'half-tone' illustrations 

 of everything from cell elements to plant com- 

 munities, and a profusion of diagrams of physi- 

 ological apparatus, with ' half-tones ' show- 

 ing the results of experiments, will take kindly 

 to this book which implies and demands 

 tvork on the part of both, remains to be seen. 

 There is a good deal of laziness in the world, 

 and we fear that the temptation to use a book 

 with pictures (which too often are studied in 

 lieu of the experiments) may be so strong as to 



