Supplanent to '* Nature T October lo, 1907 



(pump), the Gutermuth valve, and the various adapt- 

 ations of the centrifugal system of pumping, includ- 

 ing the turbine. A good portion of the book is 

 devoted to chronicling Prof. Osborne Reynolds's re- 

 searches, including an article on the theory of lubri- 

 cation. We do not notice any allusion to Prof. Hele- 

 Shaw's experiments in stream line flow, but possibly 

 this is reserved for the second volume, which is an- 

 nounced to deal with the resistance and propulsion of 

 ships. 



Altogether, there is a great deal to commend this 

 book to students and others interested in the practice 

 of hydraulics. The type is clear, the setting good, 

 and the diagrams are very distinct. There is a large 

 amount of new matter, and some old matter presented 

 in a new light, and to those who are desirous of pos- 

 sessing a record of Prof. Reynolds's investigations, the 

 volume forms a much readier source of reference than 

 the original papers and the proceedings of various 

 learned societies in which they are embodied. 



CO'Sl?AR.\TIVE Al^ATOUY OF THE 

 LABYRINTH. 

 The Labyrinth of Animals, including Mammals, Birds, 

 Reptiles, and Amphibians. By Dr. Albert A. Gray. 

 Vol. i. Pp. X+198; 31 plates. (London: J. and 

 A. Churchill, 1907.) Price 21s. net. 



ON E turns away from the examination of this work 

 with a mixed feeling in which admiration is 

 tempered with disappointment. In the volume under 

 review the author reproduces thirty-one excellent 

 stereoscopic photographs of exquisite preparations of 

 the inner ear of various species of mammals — struc- 

 tures which hitherto have been left unexplored owing 

 to the grave technical difficulties involved in their pre- 

 paration. These difficulties the author has overcome by 

 the application of a new technique whereby the delicate 

 and complicated membranous labyrinth is freed from its 

 surrounding bone, and clearly exposed as a transparent 

 body, perfect in form and texture. Besides the photo- 

 graphs of these structures, which are novelties to the 

 anatomist, the author gives scores of accurate measure- 

 ments relating to the fenestra ovalis, the semicircular 

 canals, ' and the cochlea ; careful records are given of 

 the development of the perilymph system, of the degree 

 of twisting of the cochlea, of the pigmented areas on 

 the ampullje and lamina spiralis, and of the form and 

 size of numerous other structures. The technique, 

 the industry, and the field of fresh observation compel 

 our admiration ; it is when one comes to consider how 

 far this research has really advanced our understand- 

 ing of the inner ear that a feeling of disappointment 

 creeps in. What Dr. Gray has really succeeded in 

 showing is, that the mammalian labyrinth — if the 

 monotreme form be excluded — is almost identical in 

 form and arrangement in all; the variations shown 

 relate only to minor details. That is what one ought 

 to expect, seeing how strictly the organ subserves the 

 same function in all — at least so far as it serves as 

 an organ of hearing. But as part of the mechanism 

 of balancing and of orientation, one might expect a 

 greater degree of variation in structure than Dr. Gray 

 NO. 1980, VOL. 76] 



has actually found. In the case of the sloth the semi- 

 circular canals are certainly peculiar in form. From 

 the data of comparative anatomy one is frequently able 

 to obtain valuable suggestions of the functional mean- 

 ing of obscure structures, but in this respect Dr. 

 Gray's inquiries, so far as can be seen at present, are 

 remarkably barren. 



Dr. Grav is of opinion that many of his observations 

 may afford indications of the relationship of one mam- 

 malian order to another. He divides the forms of 

 cochlea into flat conical and sharp conical. To the 

 sharp type belong the Carnivora and Rodentia, while 

 Primates, Ungulata, Sirenia, Cetacea, Insectivora, 

 and Cheiroptera possess the flat type ; the Edentata 

 show an intermediate form. Unfortunately one knows 

 so little of the real meaning of the twisting of the 

 cochlea tube that it is hazardous to say at present what 

 importance should be attached to its form. Amongst 

 marsupials, Dr. Gray found both forms of cochlea to 

 occur. He is inclined lo attach a taxonomic value to 

 the size of the perilymph space in the semicircular 

 canals, a wide space being, in his opinion, the primi- 

 tive form. The seal, for instance, has a wide peri- 

 lymph space, while the sea-lion, like the land Carni- 

 vora, has a very narrow one, from which he concludes 

 that the seal must have branched off from the primi- 

 tive Carnivora stock while this space was still wide, 

 whereas the sea-lion dates his departure from the 

 period at which this space had already diminished in 

 the land forms. To estimate the worth of such an 

 observation one wishes to be quite certain that the size 

 of the perilymph space has no functional significance, 

 and, secondly, that the wide form is really the primi- 

 tive mammalian form. Man and all the monkeys 

 possess an ample perilymph space, whereas in the 

 lemurs it is of small size. The slow loris differs from 

 the typical lemur in many points so far as regards the 

 anatomy of the inner ear, but here again one wishes 

 to know how much of this difference is really due to 

 a difference in function, and how much is really due 

 to a difference in descent. 



While expressing an unqualified admiration for the 

 results obtained by the application of Dr. Grav's tech- 

 nique, one must also admit that it is a technique with 

 very serious limitations. The finer structures of the 

 ear, the organ of Corti and the nerve-endings cannot 

 be thus examined, and are only to be explored by the 

 old, laborious and accurate method of sectional recon- 

 struction. A. K. 



BRITLSH WILD LIFE. 

 The Woodlanders and Field Folk : Sketches of Wild 

 Life in Britain. By John Watson and Blanche 

 Winder. Pp. xii + 304; illustrated. (London: T. 

 Fisher Unwin, 1907.) Price 55. net. 



THE demand for books on country life and popular 

 natural history (and from the number of volumes 

 on these subjects issued nowadays from the press it 

 may be assumed that such demand is large) is a 

 healthy sign of the times. A sine qud non with such 

 books is, however, that they should be fairly accurate 

 and reasonably up to date. Whether the volume now 



