156 



SCIENCE. 



[X. S. Vol. XVI. No. 395. 



with the external anatomy of Braula, espe- 

 cially with the structure of the mouth-parts; 

 but there is an historical account of the insect 

 and a consideration of its relations to the bee. 

 An interesting little book has been written 

 by L. C. Miall as an introduction *to the study 

 of economic entomology. The work is divided 

 into four portions ; I., Preliminary lessons ; 

 II., Lessons on common insects, chiefly such 

 as are either injurious or useful to man; III., 

 Descriptive account of the larger orders of in- 

 sects, with short notices of remarkable forms ; 

 IV., The destruction or mitigation of insect 

 pests. The book is devised especially for Eng- 

 lish students, but the introductory structural 

 and biological features would be of much 

 help to Americans. Indeed on these points it 

 is plainly superior to most of our works on 

 economic en,tomology, and indicates the lines 

 along which our text-book could be improved. 

 The economic accounts of the various species 

 treated are frequently of interest to us, and 

 the chapter on insecticides is largely drawn 

 from American sources. The outline figures 

 are good; and the book will undoubtedly do 

 much to broaden the knowledge of economic 

 entomology in England. . 



Nathan Banks. 



BOTATilGAL NOTES. 

 TWO TEXT-BOOKS OF BOTANY. 



Among recent books designed for the use of 

 students is Professor Heald's ' Laboratory 

 Manual of Elementary Biology ' (Clute & 

 Co.), Part I. of which interests us here, as it 

 alone is devoted to plants. This book is 

 interesting as coming from a teacher who has 

 had to solve the problem of the best method 

 of presenting the subject to beginning classes. 

 The method adopted is described by the au- 

 thor as a mean between the ' verification 

 method ' and the ' question method,' neither 

 of which he fully approves. Directions are 

 given for making particular observations, and 

 some questions are asked, but at the same 

 time much information is given in the text. 

 Apparently the author has succeeded in qiiite 



* ' Injurious and Useful Insects,' London, 1902, 

 8vo, pp. 2.56, figs. 103. 



successfully steering the middle course which 

 he approves. In taking up the subject he 

 begins at once with the lower plants, and 

 makes this excellent contribution to the 

 pedagogics of botany^ in his preface : " E"o ex- 

 cuse need be offered for beginning with the 

 simple forms and ending with the complex. 

 Experience has sho-mi that the logical order 

 can be carried out with even more satisfactory 

 results than the illogical order of complex 

 first and simple forms later." The book is re- 

 markable in containing no illustrations what- 

 ever, and may thus be regarded as a protest 

 against the excess of illustrations found in so 

 many recent books. Professor MacDougal's 

 little book, ' Elementary Plant Physiology ' 

 (Long-mans, Green & Co.), reminds us of his 

 earlier work, ' Experimental Plant Physiol- 

 ogy,' which in fact it is intended to replace. 

 The sequence of topics is quite different, how- 

 ever, in the new book, and many new illus- 

 trations have been added. After a useful 

 introductory chapter devoted to material, 

 measurements, etc., the author takes up 

 ' Growth,' following this with ' Eeproduction 

 and Germination.' Then follow chapters on 

 ' Exchange and Movements of Gases and 

 Liquids,' ' Nutrition,' ' Respiration, Diges- 

 tion and Eermentation ' and ' Stimulation 

 and Correlation.' The physical aspects of 

 physiology are thus first taken up, and then 

 the chemical aspects, followed by what may 

 be called the vital aspects. Here again we 

 detect a suggestion as to the proper sequence 

 of topics in the study of plants and their 

 activities. The book will no doubt become 

 popular. 



FURTHER STUDIES OF CELLULOSE. 



Several years ago a notable work appeared 

 from the hands of C. F. Cross and E. J. 

 Bevan under the simple title of 'Cellulose' 

 (Long-mans), which at once took place as a 

 standard reference book in botanical labora- 

 tories. Eecently the same authors have pre- 

 pared another book, ' Eesearches on Cellulose,' 

 brought out by the same publishers, which is 

 intended to supplement the former work. 

 It gives a brief account of the researches 

 published since the issue of the earlier book. 



