2 74 



NA 1 URE 



[January 7, 1909 



based on functional value, the functions of the various 

 tissues and organs being discussed as an introduction 

 to their intimate structure. The scope is necessarily a 

 verv wide one, and as a consequence the description 

 of detail is in many cases limited, and in some cases 

 tends to obscurity. 



The authors confine their aim to general principles 

 which shall serve as a broad foundation for further 

 studies (ziide preface). The treatise, however, is better 

 adapted as a reference book for the more advanced 

 student who has already some acquaintance with his- 

 tological detail than as a guide to one commencing its 

 study. 



Although the function of the structure is the key- 

 plan of the work, insufficient force is given to the 

 mutual interdependence of the two, the significance 

 of a structure as a functional adaptation being fre- 

 quently lost sight of. The statement in the preface 

 that " all structures exist only for the purpose of 

 performing certain functions in some particular wav " 

 is dangerous and open to misinterpretation, while the 

 statement in the text (p. 185) that nerve cells of a 

 size beyond a definite limit " are obliged to develop in 

 their cytoplasm a set of channels that will serve to 

 increase the power of nutritive exchange " is open 

 to more than criticism, and is misleading to a degree. 



The various theories as to the intimate structure 

 of protoplasm are fairly well given, but it is not made 

 sufficiently clear that the hypothetical structure of 

 protoplasm is largely founded on the examination of 

 dead tissue, and that the appearances presented by 

 tissues which have been treated by hardening and 

 staining reagents may give a very inadequate picture 

 of living matter. 



Electrical and light-producing organs are dealt with 

 in chapters replete with instruction and teeming with 

 interest, but the treatment of gas and heat production 

 is not so satisfactory. It is not sufficiently insisted 

 upon that the production of heat is a necessary con- 

 comitant of most metabolic processes, while it is 

 pushing the processes of secretion too far to suggest 

 that heat is to be regarded as the outcome of certain 

 specialised granules for which the term " theniio- 

 chondria " is proposed (p. 141), or that the gas which 

 fills the swim-bladder of a teleost fish first appears 

 in special gas-secreting cells in the form of granules 

 (P- 3j4)- 



Chondrostosis involves a bewildering succession of 

 complicated changes, a convincing account of which 

 has yet to be written. A perusal of its description 

 in the work under notice (p. 70) will not bring con- 

 fused ideas into order. The changes taking place are 

 described as a transformation of hyaline cartilage into 

 bone, that the process is fundamentally neoplastic not 

 being recognised. The statement that " when ossi- 

 fication begins a vascular loop enters the bone bring- 

 ing with it the various bone-making cells " endows 

 the blood-vessel with a potency of active migration 

 which it certainly does not possess; the so-called 

 vascularisation of the cartilage certainly involves an 

 active migration of cellular tissue, but the vessels 

 which appear therein undoubtedly develop in situ. 

 A description of the intermediate stage, the forma- 

 NO. 2045, VOL. 70] 



tion of a temporary metaplastic bone represented by 

 the calcification of the cartilage, is omitted, the de- 

 position of the lime salts being entirely ascribed to 

 the osteoblasts. That the bone formation begins in 

 the middle of the " joint " of an embryonic finger is 

 a novel use of the term joint ; it is perhaps popularly 

 correct, but not to be expected in a scientific text-book 

 as a term defining a digital segment. Bone, it is 

 stated, can be formed in the connective tissue, but 

 no account is given of parostosis, and this omission 

 is a serious one. 



Vertebrate histology, on the whole, receives scant 

 treatment, and this will be felt in studying the abbre- 

 viated descriptions of the retina (p. 255 et seq.), the 

 organ of Corti (p. 221), and the organs of digestion 

 (chapter xv), but the authors hint that such matters 

 are adequately dealt with in medical text-books, and 

 this relative deficiency is more than compensated for 

 by such able and comprehensive contributions as the 

 section? dealing with nephridial tissues, mechanical 

 protection, poisonous fluids, &c. 



The book is richly illustrated ; the figures, for the 

 most part in black line, are exceedinglv clear and 

 instructive, and add vastly to the value of the work 

 as a whole. Many of the illustrations are original ; 

 others are selected from well-known sources with a 

 wise discrimination. 



The chapter on " technic " (!), although very abbre- 

 viated, gives a good practical outline of general 

 methods of hardening and staining, but the sugges- 

 tions, scattered throughout the text, as to the methods 

 for elucidating the details of special tissues are scanty 

 in the extreme, and of no practical value. 



The whole bibliography is slender ; the authors 

 seem to have relied largely on the results of their own 

 original research ; this, however, adds greatly to the 

 intrinsic value of the work. Typographical errors are 

 numerous; " Haidenhain " in the text, and the titles 

 of French and German papers quoted on pp. 166, 173, 

 501, &•€., stand in need of correction. 



With some amendments in the text, a few more 

 details concerning the preparation of tissues for ex- 

 amination, and a more complete bibliography, Messrs. 

 Dahlgren and Kepner's treatise will prove an in- 

 valuable addition to the library of the biologist. 



7.V/U.1.V WILD-FOM'L. 

 The Indian Ducks ami their AUics. By E. C. Stuart 

 Baker. Pp. xi-l-2q2 ; illustrated. (Bombay : Natural 

 History Society; London: R. H. Porter, 1908.) 

 Price 2I. 2s. net. 



THE enormous flocks in which many members of 

 the duck tribe visit the plains of India during 

 the cold season, coupled with the relatively large 

 number of species by which the group is there repre- 

 sented, affords ample justification for the issue of this 

 handsome and superbly illustrated volume. For these 

 swarms of ducks, geese, swans, and mergansers 

 naturally attract the attention of a host of sportsmen, 

 many of whom are anxious to identify the species of 

 the birds which go to form their bag, and ascertain 

 something about their natural history. Neither is thu 



