June 22, 1893] 



NA TURE 



i«5 



Ihe posterior ampulla is innervated from the cochlear nerve), 

 the unfortunate bearings of which upon certain much more 

 recent physiological speculations he is not slow to point out 

 (p. 148). The thanks of all teachers are similarly due to the 

 author, for having introduced the peculiarly appropriate term 

 "ama" for that second and non-sensiferous enlargement of the 

 canals met with in the lower and the highest classes of verte- 

 brates, and for the substitution of " external " for the misleading 

 "horizontal " canal. 



One very remarkable discovery, which the author deals with 

 only too casually, is that " in many forms of Elasmobranchs the 

 ear contains scarcely any crystals, and not unfrequently sand 

 grains." The interest of this, by analogy to Hensen's well- 

 known experimental observations upon the Decapod Crustacea, 

 will sufficiently appeal to all zoologists ; and we sincerely hope 

 the author will early furnish us with particulars concerning it. 



II. Revolutionary as may be some of the author's conclusions 

 above cited, the refrain of the major part of his morphological 

 inquiry is, on the whole, no less so. It runs as follows : — 

 "There can be no doubt that the internal ear develops from 

 superficial canal organs"; that it is primarily subdivided into 

 anterior and posterior portions ; and that a "fateful distortion," 

 under which the great development of the cochlea drags the 

 posterior half downwards, has "perhaps more than anything 

 else " deceived us and "retarded our progress in the knowledge 

 of the significance" of its parts. Thus it is that the author 

 gives definiteness to a view which, although it unconsciously 

 dawned with Leydig's recognition of structural similarity be- 

 tween the auditory and tegumental-canal sense-organs of the 

 Ichthyopsida, was first definitely formulated by Beard. He 

 takes his stand upon Beard's brilliant generalization, as modi- 

 fied by the acceptance of Froriep's interesting correction (p. 

 314), and by certain considerations arising out of his own in- 

 quiry. In the performance of this task the author has been 

 shoulder to shoulder with Mr. Allis, co-editor and joint founder 

 oi ihe Journal of Morpho/pgy, and author of one of the most 

 remarkable papers which its pages have yet borne, viz. that 

 upon "The Anatomy and Development of the Lateral Line 

 System in Amia Calva," duly noted in these pages (Nature, 

 Aug. 29, 1889), and nothing is more apparent than that 

 he has sought to extend the laws of growth which Allis 

 discovered for the lateral line organs to the internal 

 auditory one. His leading deduction that the last named 

 structure consists of "a symmetrical group " of the organs in 

 question chiefly rests upon the following discoveries and allega- 

 tions, apart from any question of general structural resemblance 

 between the two, viz. (i.) the lineally recurring (antero- posterior) 

 symmetry of the parts of the labyrinth ; (ii.) the duplication 

 of the endolymphatic duels in Cyclostomes and some Elasmo- 

 branchs ; (iii. ) the double and repetitional nature of the auditory 

 nerve — that being regarded as a derivative of "two distinct 

 cranial nerves," consining of an anterior (utricular) fasciculus 

 in anastomosis with the facial, and a posterior (cochlear) one, 

 either in astomosis with the glossopharyngeal, or totally inde- 

 pendent ; and (iv.) an attempt to show that ihe mach/a acoustica 

 negUcla\i3.\\ "abortive second horizontal canal organ." Although 

 inclined to accept the general tenor of the author's broader 

 morphological conclusions, we cannot concur in the last cited 

 one. He formulates it almost entirely upon the study of nerve 

 distribution ; and, by his own showing {pp.-28, 29) the sensiferous 

 area in question might well have had an independent origin. 

 The conclusion does not, however, materially affect the author's 

 dictum, and in respect to it he seems to have been carried away 

 by a bias in favour of Allis, which elsewhere reappears 

 (PP- 275, 277, and 283), and culminates in the unwarrant- 

 able assertion (p. 308) that "the semicircular canals of the ear 

 are simply remnants of the canal system of the surface" (p. 318) 

 " not known to have any other function than the one inherited 

 from their ancestors, viz. that of serving as mechanical pro- 

 tectors of the sense organs," and that they are to be classed with 

 such structures as valves in the horizontal veins . . . the 

 vermiform appendix . . . and atavistic muscles " (jiV). Having 

 sought to sb.iw that the "canal organ has been gradually losing 

 ground" during the progress of descent with modification, the 

 author argues (p. 235) that the future human ear "will not retain 

 much else than the cochlea"! What of the adherents to the 

 bagpipe? We would recommend a periodical examination of 

 their ears to the author's notice. Statements of the order here 

 cornmented upon are indicative of haste and over-enthusiasm, 

 while others, to the effect that (p. 47) "the cells involuted with the 



NO 1234, VOL. 48] 



sensory structures "merely" serve as a lining of the auditory cana 

 chambers," and that the otoliths, which they secrete (p. 309) 

 " are to be considered as essentially foreign bodies . . . toler" 

 aled because of the impossibility of getting rid of them . 

 and the result of the secretive action of the ectoderm cells, which 

 in ancestral forms produced the surface scales," are little short 

 of nonsensical. 



With Fritsch, the author regards the Savi's vesicles of the 

 ^(r/«rf«!' as derivatives of "the widespread open canal type" 

 of organ ; and by no means the least striking portions of his 

 treatise are those in which he attempts to prove (i.)that the 

 semicircular arch of Myxine is " composed of the anterior and 

 posterior vertical canals of the Gnathostome vertebrate ear" — 

 deducing an argument in favour of the non-degeneracy 

 of the Marsipobranchii, and (ii.) "that a comparison of the 

 ears of Myxine, Petronnyzon, Dasyatis, Torpedo, and Man 

 clearly shows the connection of the [endolymphatic] duct with 

 the utricular and sacular chambers to be a fundamental 

 condition, and not a secondary acquirement." 



III. That the physiological aspects of the author's inquiry 

 might be expected to be no less sensational than the morpholo- 

 gical ones, is sufficiently clear from his eailier surmise (pamphlet 

 No. 7 of literature cited) that (p. 8) "when one consideis the 

 truly wonderful auditory powers" of the mocking bird, "it be- 

 comes evident that we must seek for some explanation which 

 does not involve the piano-stiing hypothesis," and that (p. 9) 

 " it is perfectly obvious that we do not need an internal ear in the 

 vertebrate organization for the perfect exercise of the function of 

 equilibration, since in Amphioxus the organ is absent, and in 

 higher forms the auditory nerves may be destroyed without des- 

 troying this function." Little wonder, then, that the author should 

 denounce both the "statical" theory ofGollz, and the more 

 recent "dynamical" one of Cyon, Crum-Brown, and later 

 expeiimentalists. His attitude towards the majoriiy of his pre- 

 decessors is best expressed in his remark that "all the pheno- 

 mena following canal section in mammals and in birds are 

 nothing more than the results of brain lesions such as are 

 entirely inadequate to explain " them. 



Availing hinr.self of the observations of Munk, that, whereas 

 in the dog, destruction of the ear, which may lead up to fatty 

 degeneration of its inner constituent, is "always followed by 

 dizziness and equilibrative disturbances, such disturbances do not 

 appear when the cochlea is preserved," and of others akin to them 

 he concludes that, provided the semi-circular canals " have a func- 

 tion, it is not either statically or dynamically equilibrative." 

 Reference is made to Steiner's important observation that whether 

 (in the shark) "the semicircular canals were removed or not," 

 disturbance of the otoliths covering the utricular sense organ, 

 invariably instituted rolling movements, usually towards the 

 side disturbed ; but the author is silent concerning Engelmann's 

 attempt to assign distinct functions tothecristre and maculse 

 with theirs associated otolithic masses. Indeed, his opening 

 statement (p. 237) that " we have very slender foundation for 

 forming final judgments of the functional relations of any 

 pans of the internal ear, and that at present what we impera- 

 tively need isnotspecniation, but e.xpeiimenlatioii," vieW defines 

 our position to-day, when the sum of the author's own experi- 

 mental observations are taken into account. The phjsiological 

 section of his work is much weaker and less extensive than its 

 morphological ally. 



IV. The author is to be congratulated upon an unusually 

 speculative treatise, embodying a substratum of solid work. As 

 a "paper" it is, in its bulkiness, a sort of awful example fit to 

 rank with that of his countryman Mark on the egg of Umax 

 camfesti-is {Bull. Mus. Comp. Zobl., vol. vL, 445 pages in all). 

 The publication of such voluminous treatises in any but book 

 form, provided with an analytical index, is unjust to both 

 author and reader. It is a gross mistake, and the author has 

 but himself to thank if he escapes proper recognition in conse- 

 ([uence. Much of the said bulkiness of the present tiealise is 

 due to the incorporation of needlessly lengthy citations 

 from foreign writers, which, permissible in a book, are 

 out of place in a "paper" intended for specialists pos- 

 sessing a full knowledge of current literature. We could have 

 wished, instead of these, a recognition and an explanation of 

 topics untouched ; for example, of the circular condition of the 

 posterior canal among the depressed Baloidei, which the 

 author's remarks on pp. 13, 16, 222, and 223 by no means 

 sufficiently express, and which is inexplicable on his belief that 

 "the mechanical forms active in the modelling of the ear are 



