Search

The anatomical study of an animal is chiefly a matter of applying a certain practical method of exposition, the student's attention being concentrated on those facts which can be made out by direct observation. This method is educative in the technical sense because it involves accurate discernment of detail, and because, as a means of obtaining first-hand information, it is the foundation of laboratory practice. This being the case, it is a very pertinent question what is the best procedure. So far, as the present book is concerned, it is expected that the study of the type will begin with at least a preliminary survey of the prepared skeleton (Part II). This will be followed by dissection (Part III), in which the order by sections will be found of less importance than that of details in any particular region and and in which portions of the skeleton related to the part under examination may be included.The regional method of approach is indicated rather than the more complete study of single systems, partly for the sake of economy of material and partly in belief that this aids understanding of the topographical and other interrelations between systems, encouraging the building up of a conception of the individual organism as an integrated unit.The general matter of Part I is purely accessory and, though necessarily incomplete in many ways, is designed to afford a comprehensive view of the various factors upon which mammalian structure depends. It will be found that only the first few chapters are introductory in most respects, the remainder being rather explanatory and hence most valuable if used to supplement the directions for dissection as this is carried out.In preparation of the eighth edition of the Practical Anatomy of the Rabbit use has been made of extensive notes recorded in the laboratory during successive years of employment of the previous edition. All relevant questions raised by students or other instructors for which an adequate answer was found not to be readily available in the text have been noted and an attempt has been made to provide answers for them in the revisions. The whole text has been searchingly surveyed with the result that many small changes have been made, parts have been expanded, and a few have been entirely rewritten.

Although the ferns and their allies are a small group of about 10,000 species compared to the 275,000 species of seed plants, their lineage is a long and noble one going back to the carboniferous period 300 million years ago when they were the dominant form of plant life in the swap-forests. Ninety-seven species of attractive group of plants are described in this this column, about one-quarter of the total found on the whole continent north of the Mexican border. Each species is described in detail, and the description is supplemented by a clear line drawing and a map showing its distribution as represented in the larger collections of the continent. The drawings are original and based on specimens carefully selected the show diagnostic details. Keys are provided to the families, genera, and species so that a plant can be placed quickly and easily in its proper category. The book also includes a list of chromosome numbers, a list of species grouped by distribution patters, and a glossary of the technical terms used. This is the first comprehensive treatment of the pteridophyte flora of the large area comprising Oregon, Washington, British Columbia, the Yukon Territory, and Alaska to the Arctic Ocean. In this region, climate varies from warm to arctic cold, precipitation varies from 200 inches annually to less than 10, and altitude varies from sea level to over 20,000 feet. Arranged in alphabetical order by family, genus, and species, this volume brings together in convenient form the critical judgments of experts who have written about the pteridophyte flora of the Northwest. Both the professional biologist and the naturalist will find much in this volume of interest and value.

Dr. Walker makes a signal contribution in gathering together all available information on the dragonflies of Canada and Alaska. The order as a whole and the zygoptera are covered. The treatment is not confined to taxonomy and geographical distribution, but includes data on habitats, seasons of adult life, and brief notes on habits when these are available.

Dr. Walker makes a signal contribution in gathering together all available information on the dragonflies of Canada and Alaska. The order as a whole and the zygoptera are covered. The treatment is not confined to taxonomy and geographical distribution, but includes data on habitats, seasons of adult life, and brief notes on habits when these are available.