LITERARY NOTICES. 



75 



Barnard and Agassiz, which will be 

 sustained by every intelligent critic 

 who looks into it, wo submit that the 

 question of compulsion is premature ; 

 if any system is to be enforced, let it 

 bo a rational one. 



LITERARY NOTICES. 



Key to North American Birds, contain- 

 ing a Concise Account of every Species 

 of Living and Fossil Bird at present 

 known upon the Continent north of the 

 Mexican and United States Boundary. 

 Illustrated by Six Steel Plates and up- 

 ward of 250 Woodcuts. By Elliott 

 Coues, Assistant Surgeon United States 

 Army. Boston : Estes k Lauriat. New 

 York: Dodd & Mead, 1872. 



This exhaustive and beautifully - exe- 

 cuted folio comes to us as an exponent of 

 the present state of American ornithologi- 

 cal science. The position of Dr. Coues as 

 a naturalist is a guarantee of the character 

 of his work. He lays under contribution 

 the latest results, having been assisted by 

 various eminent gentlemen, while a large 

 part of the volume consists of his own ori- 

 ginal observations. While the work is at- 

 tractive to all who care for this fascinating 

 subject, the author has nevertheless aimed 

 at strict scientific accuracy in his state- 

 ments. At the outset he puts the question, 

 " What is a bird ? " and most people would 

 think the answer very simple, but in such 

 matters most people are apt, unhappily, to 

 be mistaken. How loose and insufficient 

 the common notion would be as compared 

 with the conception of science, may be 

 shown by quoting the answer that Dr. 

 Coues gives to his own question : " A bird 

 is an air-breathing, egg-laying, warm-blood- 

 ed, feathered vertebrate, with two limbs 

 (legs) for walking or swimming, two limbs 

 (wings) for flying or swimming, fixed lungs in 

 a cavity communicating with other air-cavi- 

 ties, and one outlet of genito-urinary and di- 

 gestive organs ; with {negative characters) no 

 teats, no teeth, no fleshy lips, no external 

 fleshy ears, no (perfect) epiglottis nor dia- 

 phragm; no bladder, no scrotum, no cor- 

 pus callosum ; and with the following col- 

 lateral characters, mostly shared by more 

 or fewer other animals : under jaw hinged 

 with the rest of the skull by means of an 



interposed movable bone, that is also mov- 

 ably jointed with two bones of the upper 

 jaw; head jointed with neck by only 

 one hinge; shoulder-joints connected with 

 each other by a curved bone, the clavicle 

 (with rare exceptions), and with the breast- 

 bone by a straight, stout bone, the cora- 

 coid ; ribs all bony, most of them jointed 

 in the middle as well as with back-bone 

 and breast-bone, and having offsets; less 

 than three separate wrist and hand bones ; 

 two fingers, of one or two bones ; head of 1 

 thigh-bone hinged in a ring, not in a cup ; 

 one of the two leg-bones not forming the 

 ankle-joint ; no separate ankle-bones ; less 

 than three separate foot-bones ; two to four 

 toes, of two to five bones, always ending in 

 claws ; both jaws horny-sheathed and nos- 

 trils in the upper one ; feet and toes (when 

 not feathered) horny-sheathed; three eye- 

 lids ; eyeball with hard plates in it, eight 

 muscles on it, and a peculiar vascular organ 

 inside ; two larynges, or ' Adam's apples ; ' 

 two bronchi ; two lungs, perforated to send 

 air into various air-sacs and even the inside 

 of bones ; four-chambered heart, with per- 

 fect double-blood circulation ; tongue with 

 several bones ; two or three stomachs ; one 

 liver, forked to receive the heart in its 

 cleft; gall-bladder or none; more or less 

 diffuse pancreas or sweet - bread ; ' a 

 spleen ; intestines of much the same size 

 throughout ; caeca or none ; two lobulated, 

 fixed kidneys; two testicles fixed in the 

 small of the back, and subject to periodi- 

 cal enlargement and decrease; one func- 

 tional ovary and oviduct ; outlets of these 

 last three organs in an enlargement at end 

 of intestine, and their products, with refuse 

 of digestion, all discharged through a com 

 mon orifice. But of all these, and other 

 characters that come under the head of de- 

 scription rather than of definition, one is 

 peculiarly characteristic of birds ; for every 

 bird has feathers, and no other animal has 

 feathers " 



Mysteries of the Voice and Ear. By 

 Prof. 0. N. Rood, of Columbia College. 

 Chatfield & Co., New Haven. Univer- 

 sity Series. 



This pamphlet is one of the most ad- 

 mirable expositions of its subject that we 

 have ever read. Prof. Rood is one of our 

 first physicists, the author of many valuable 



