March 23, 1900.] 



SCIENCE. 



467 



botauy,' while this is said to be 'a second boolc.' 

 The former ('Plant Relations') attempted to 

 treat the subject from an ecological standpoint, 

 and in our opinion the author failed to make it 

 'a first book'; in the present volume morphol- 

 ogy is the dominant subject, and, as if in some 

 doubt himself, the author says in the preface : 

 "It may be, however, that many teachers will 

 prefer to begin with the morphological stand- 

 point as given in this book. Recognizing this 

 fact ' Plant Structures ' has been made an inde- 

 pendent volume that may precede or follow 

 the other, or may provide a brief course of 

 botanical study in itself." This remarkably 

 flexible purpose has been well carried out by 

 the author. He has made an excellent first 

 book of botany, in spite of its title. 



The book follows the approved sequence from 

 the simpler to the more complex plants, and 

 the treatment is that which has been developed 

 in the best botanical laboratories. The very 

 helpful 'Suggestions to Teachers,' prepared by 

 Dr. Caldwell to accompany the book, empha- 

 size the practicability of the course here out- 

 lined. One feels as he runs over the pages that 

 he is on ground which has been traversed 

 again and again by teachers and pupils, and 

 that all the work outlined can be done, because 

 it has been done again and again. 



We should like to take up the chapters in 

 detail, but that cannot be done in a brief notice. 

 We could ask here and there for a less confus- 

 ing sequence (e. g., where Slime Moulds and 

 Bacteria are taken up after Toadstools and 

 PufFballs, and Coleochsete in the midst of the 

 Bryophytes), and far less of generalization be- 

 fore the pupil has some facts in hand (e. g., in 

 Chapter III., where the evolution of sex is dis- 

 cussed when he is as yet in total ignorance of 

 the structural facts on which the theory is 

 hung). On the other hand, the author's gen- 

 eralizations in the form of summaries from pre- 

 ceding groups (e. g., Thallophytes, Bryophytes 

 and Pteridophytes), are admirable. 



The illustrations are good, and well chosen. 

 Many have a delightful freshness, in sharp con- 

 trast to the well-worn cuts so long familiar in 

 similar text-books. 



Charles E. Bessey. 



The Univeesity of Nebraska. 



Observations made at the Blue Hill Meteorological 

 Observatory, Massachusetts, U. S. A., in the 

 Yea7-s 1897 and 1898. Under the direction of 

 A. Lawrence Rotoh, A.M. With an Ap- 

 pendix containing the International Cloud 

 Measurements during 1896-97. Annals of the 

 Astronomical Observatory of Harvard Col- 

 lege. Vol. XLII. Part II. 4to. Cambridge, 

 1900. Pp. 131-280. 



The cloud work done at Blue Hill Observa- 

 tory is known to meteorologists the world over, 

 the publications on clouds already issued by 

 this Observatory having been among the most 

 important contributions to meteorology in re- 

 cent years. This satisfactory result has been 

 made possible through the liberality of BIr. A. 

 Lawrence Rotch, the founder and director of the 

 Observatory, and through the admirable work 

 done at the Observatory by Mr. H. Helm Clay- 

 ton and his associates, Messrs. S. P. Fergusson 

 and A. E. Sweetland. Mr. Clayton's Discussion 

 of the Cloud Observations made at Blue Hill (An- 

 nals Harv. Coll. Obs'y, Vol. XXX., Part IV.), 

 is the most complete publication on clouds ever 

 issued (see Science, N. S., Vol. V., 1897, pp. 

 468-469). When the ' International Cloud 

 Year' was begun on May 1, 1896, in accord- 

 ance with the recommendation of the Interna- 

 tional Meteorological Committee in 1894, the 

 Blue Hill Observatory was one of the stations 

 in the United States which co-operated in this 

 special work, the other stations being those 

 under the jurisdiction of the Weather Bureau. 

 The present volume includes the usual meteor- 

 ological observations made during 1897 and 

 1898, publication of which was delayed in order 

 that an appendix containing a discussion, by 

 Mr. H. H. Clayton, of the Measurements of 

 Cloud Heights, Velocities and Directions, carried 

 out during the ' Cloud Year,' might be included. 

 In this Appendix are printed the tables con- 

 taining details of all the cloud observations 

 made throughout the 'Cloud Year,' together 

 with tables showing the mean heights and mean 

 velocities of the clouds at different hours and 

 seasons ; the number of clouds and measure- 

 ments ; the mean, maximum and minimum 

 heights and velocities by months ; the mean 

 heights with different temperatures and pres- 

 sures ; the mean heights with different gradi- 



