SCIENTIFIC LITERATURE. 



99 



of classification and of the relations and 

 development of organic life on the globe 

 would find a place. This task pre- 

 sented many difficulties, both for the 

 revisers and for the editor, and one can 

 not but regret that the cost of illus- 

 tration and the difficulties of finding 

 a publisher for a wholly new work 

 stood in the way of preparing a manual 

 which should be avowedly, as well as 

 practically, independent. The excel- 

 lent work of von Zittel, good as it is, 

 was designed on the lines of the science 

 as it was a quarter of a century ago. 

 The revision, though in several depart- 

 ments fundamental, is naturally more 

 or less uneven, the restrictions of space 

 insisted on by the publishers and 

 other causes hampering the freedom of 

 treatment desirable, while the compos- 

 ite nature of the work, part of which 

 was stereotyped before other portions 

 were received in manuscript, has inev- 

 itably resulted in some incongruities. 

 However, in spite of such minor de- 

 ficiencies, the result has been the most 

 notable advance in the treatment of in- 

 vertebrate paleontology as a whole 

 since text-books began to be made. 

 This is especially evident in such 

 groups as the Polyzoa, Mollusca, 

 Brachiopods and Trilobites, in which 

 the illustrations and a part of the bib- 

 liography are all that remain of the 

 older work. Any work in which the 

 latest views of large divisions of the 

 animal kingdom are summed up by 

 such experts as Wachsmuth, Ulrich, 

 Schuchert, Hyatt and Beecher must ap- 

 peal strongly to students and long re- 

 main an indispensable aid to science, 

 whether all matters of detail meet with 

 final acceptance or not. Wholesale 

 changes, such as are indicated in sev- 

 eral of the groups, might very well be 

 unacceptable to the original author of 

 the work thus modified, but, while sus- 

 pending his opinion on the advisability 

 of some of the novel methods, Dr. von 

 Zittel, in his preface to the present 

 work, has been moved by the true 

 scientific spirit which, while holding 

 fast to that believed to be good, is ever 



ready to welcome any new light. The 

 untouched riches of American fossilifer- 

 ous horizons, especially above the 

 Paleozoic, are almost incalculable, and 

 the existence of Dr. Eastman's valuable 

 text-book can not but be a most impor- 

 tant factor in the training of those who 

 will hereafter bring to light the riches 

 now awaiting the advent of paleonto- 

 logical explorers. 



ZOOLOGY. 



There has been somewhat of a 

 dearth of works on natural history dur- 

 ing the past few months. Among those 

 which have appeared is 'Nature's Cal- 

 endar,' by Ernest Ingersoll, a book in- 

 tended to stimulate the reader's power 

 of observation by inducing him to note 

 down, day by day, what he sees going 

 on in the world of animals and plants 

 about him. There are twelve chapters, 

 one for each month, in which the au- 

 thor writes pleasantly of what is being 

 done by the more familiar beasts and 

 birds, reptiles, fishes and insects, as well 

 as plants, in an ordinary season in the 

 vicinity of New York. The limits, 

 however, have not been very rigidly 

 drawn, and we read of deer, bears and 

 wildcats, animals not commonly found 

 about that city. We are told, as the 

 case may be, how animals and plants 

 are guarded against extremes of heat 

 and cold, at what time the animals 

 make their appearance, when the wood- 

 chuck comes from his burrow and the 

 shad and herring ascend the streams; 

 when they mate; at what time the eggs 

 are deposited or the young come forth; 

 at what time the buds burst and the 

 blossoms open, and of many other oc- 

 currences. Each chapter is preceded by 

 a full-page plate, after photographs by 

 Clarence Lown, of some landscape in 

 accord with the text, and at the end of 

 each chapter is a 'calendar,' in which 

 the birds naturally appear in the major- 

 ity, stating what animals are present, 

 the approximate times at which, if they 

 migrate, they come or go, or the dates 

 on which they go into or come out of 

 winter quarters. The compact text oc- 



