Bibliographical Notices. 237 



to those external characters which were the sole guides of the early 

 systematists, but also to those anatomical and physiological facts 

 which constitute the framework of philosophic zoology ; the scalpel 

 and the needle have long since done their work, and of late years the 

 microscope has revealed some valuable characters in the arrangement 

 of the bone-cells, and the relative measurement of the blood-cor- 

 puscles. The relative size of the sexes, the food, the habits, whether 

 ordinary or under parental emotions, the mode of nidification, the 

 number of eggs, the appearance presented by the new-born young, 

 their comparative powers of vision, and of terrestrial or aquatic loco- 

 motion, are all more or less valuable accessories * to successful enter- 

 prise in a field of research so varied and extensive as to tax all the 

 mental and bodily powers of " the close-pent thinker and the busy 

 worker." 



An interval of nearly twelve years having elapsed smce the publi- 

 cation of the first volume and the appearance of those placed at the 

 head of this article, it may be useful to remind our readers, that in 

 the introduction, the author ably enforces the claims of comparative 

 anatomy to be considered, not as a mere adjunct to, but an integral 

 part of, scientific zoology. In the three first volumes will be found, 

 besides an explanation of the terms employed in describing the ex- 

 ternal characters, a series of compendious remarks on the skeleton, 

 the trachea or windpipe, and the interior parts, especially the gullet, 

 stomach, intestinal canal and its appendages, which bear undeniable 

 traces of deep research and thoughtful elaboration. Educated for the 

 medical profession, called to the Conservatorship of the College of 

 Surgeons in Edinburgh for many years, the friend chosen by the 

 lamented Audubon to dissect, describe, and illustrate the anatomy of 

 many hundreds of specimens of American birds preserved in spirits 

 for that purpose, the author has brought to the due cultivation 

 of such rare opportunities an active and inquiring mind, unwearied 

 dihgence, great perseverance, a delicate pencil and a ready pen. To 

 these high qualifications for the closet and the field must be added, 

 the rare opportunities he enjoyed and improved of visiting many of 

 the choicest localities for the study of the habits of his feathered 

 favourites, more especially the "Water-birds, popularly so called, to the 

 elucidation of whose history these volumes are devoted. 



True to his early behef in the importance of anatomic structure, 

 the author neglects no opportunity of illustrating its worth and 

 enforcing its practical application. The position of the Cranes 

 (GruincB) is disputed by many : " although they bear some consider- 

 able resemblance to the Herons and Storks, they are clearly not of 

 that family, but more alUed to the Bustards and Plovers, their very 

 muscular stomach and double caeca being sufficient to separate them 



* So also are Mr. Denny's researches on the parasitical Anoplura, and 

 our author gives the value of the Entozoa in his remarks on British Swans. 

 The Guillemot deposits her egg on the bare rocky shelf, the Woodpigeon 

 on an open platform of sticks, the Wren in a dome-shaped nest : a micro- 

 scopic examination of the egg-shell, as well as the down of young birds, 

 would lead to much curious, if not useful, information. 



