Febeuaey 23, 1900.] 



SCIENCE. 



309 



female parent, or simply false hybrids de- 

 veloped from adventive embryos. It is thus 

 probable, or we may say certain that in 

 such work many seedlings will have to be 

 grown and fruited which are from adven- 

 tive embryos and are not true hybrids. 

 These of course cannot be expected to give 

 rise to valuable new varieties, and growing 

 them will greatly increase the trouble and 

 expense. 



W. F. Ganong, 



Secretary. 



SCIENTIFIC BOOKS. 

 Insects, their Structure and Life. By Gboege H. 



Carpenter, B.Sc. London, J. M. Dent & 



Co. 1899. Pp. 404, figs. 183. 



There is need of a modern elementary text- 

 book of entomology covering all the important 

 phases of the study of insects. Comstock's 

 Manual in its present form is chiefly devoted 

 to the systematic and ecologic phases, while 

 Packard's new text-book is given up exclu- 

 sively to the morphological, physiological and 

 developmental phases of insect biology. Mr. 

 Carpenter's book is an attempt to supply the 

 need. Its six chapters treat respectively of the 

 Form of Insects (anatomy and, very slightly, 

 of physiology), the Life-history of Insects (em- 

 bryonic and post-embryonic development), the 

 Classification of Insects, the Orders of Insects 

 (these two chapters including the classification 

 of insects as far as families, and brief mention 

 of the habits with families as units). Insects 

 and their Surroundings (ecology) and the Pedi- 

 gree of Insects (phylogeny). These subjects 

 include all the principle phases of the general 

 biologic study of a group of animals, and in 

 this respect the book .is wisely planned to meet 

 a real need. For the most part this presenta- 

 tion of the elementary facts of the 'structure 

 and life of insects' will meet with the approval 

 of teachers of entomology. The selection from 

 the mass of material constituting the science of 

 entomology of the little that can be included in 

 an octavo volume of 400 pages, is a matter re- 

 quiring a large knowledge of insects and a dis- 

 criminating and clear pedagogic insight. The 

 author (an active naturalist of Dublin) has a 



good knowledge of entomology, a discriminat- 

 ing perception of the relative importance of 

 facts, and a clear and simple style. 



In undertaking to write an elementary gen- 

 eral text-book of entomology, the most diflScult 

 task is that of the satisfactory treatment of the 

 systematic phase. The enormous number of 

 insect species precludes the use in such a book 

 of classificatory units smaller than families, and 

 indeed renders the adoption of the family unit 

 unsatisfactory. It is this part of the book, the 

 chapter, Orders of Insects, devoted to the sys- 

 tematic consideration of insects, which is the 

 least satisfactory part of it. To treat syste- 

 matically the whole class of insects, using 

 families as units, in a few more than one hun- 

 dred octavo pages, and to impart to this treat- 

 ment any real interest or life, or, one is forced 

 to say, real value, is too nearly impossible to 

 be expected from even the capable author of 

 this book. He adopts a 15-order classification 

 and races through these orders, leaping family 

 barriers three or four to the page. To be sure, 

 certain mechanical assistance, a resorting to 

 small type, is offered to give each family a 

 chance to have its habits told in two lines in- 

 stead of one, but that hardly betters matters. 

 There is simply no space for what is the abso- 

 lute minimum of treatment necessary to make 

 such a syllabus or synopsis worth anything 

 more than a list. 



It is with relief, therefore, that we leave this 

 distressful attempt to do the impossible, to ex- 

 amine the following interesting and admirable 

 chapter on 'Insects and their Surroundings,' 

 where those general relations of insects to their 

 surroundings, distribution, parasitism, protec- 

 tive resemblances and mimicry, social and com- 

 munal life and other phases of insect ecology, 

 are presented. Similarly good are the chapters 

 on embryonic and post-embryonic development. 

 Much of the matter of these chapters has 

 never before been given in a small text-book of 

 entomology, and that is the special value of 

 this book. The illustrations are, while mostly 

 good in themselves, often not very apposite to 

 the context. Very few new figures have been 

 made for the book. The excellent blocks (more 

 familiar to American entomologists than they 

 probably are to English students) of the Divi- 



