188 Bibliographical Notices, 



secondly of the optic lobes, and thirdly of the medulla oblongata and 

 cerebellum, while the olfactory lobes, as being serially homologous 

 to the optic, have been designated by the apt appellation of rhinence- 

 phala; secondly, by the eminently suggestive observations at pp. 187, 

 190, relative to the functions performed by the different portions of 

 the brain, more especially of the prosencephalon and cerebellum, the 

 last of which, after a careful comparison of its degrees of develop- 

 ment as evidenced by the " sluggish Rays " and " vigorous Sharks," 

 our author inclines to believe is very directly subservient to the 

 power of locomotion. How fully were we convinced, upon reading 

 this, of the profound truth of a remark made by Oken in his * Naturphi- 

 losophie,' " that the reason why we have as yet wandered to and fro, 

 without main-stay and without compass, in the pursuit of mental phi- 

 losophy, rests solely in the disregard that has been paid to the know- 

 ledge or science of nature !" Would we essay to decipher the psychical 

 functions and their allotted organs in the human brain, recourse must 

 be had less to experiment than to the study of that organ throughout 

 the Vertebrate series ; " since (p. 187) it may well be doubted whether 

 nature ever answers so truly when put to the torture, as she does 

 when speaking voluntarily through her own experiments, if we may 

 so call the ablation and addition of parts which comparative anatomy 

 offers to our contemplation." To follow our author through the rich 

 record of facts and reflective observation contained under the head 

 just alluded to, and including the special organs of sense and elec- 

 tric apparatus, or into the dental and digestive, followed by the vas- 

 cular, system, a masterly account of the air-bladder in the lecture 

 devoted to the pneumatic and renal organs, or finally into the ela- 

 borate description of the generative system and developmental pro- 

 cess in the class of Fishes; would be but to multiply quotations and 

 gratify an idle and temporary curiosity on many important points, 

 which, to be fully appreciated, must be read in their proper places 

 along with the context, where each fact and its interpretation form 

 but the linked parts of one great Whole. We hasten therefore at 

 once to indulge in a few words concerning that which has been 

 omitted hitherto, expressly that it might be last mentioned, seeing 

 that it constitutes a large portion of the present volume, and from 

 the objects whereof it treats, and the manner in which that is effected, 

 deservedly forms the most valuable and novel feature, paramount to 

 every other perfection in this goodly contribution to British science, 

 while it lays claim to presaging a new dawn or mental epoch in the 

 career of biological investigation. We allude to that which is the 

 principal subject-matter of Lectures II. to VI. inclusive, where, in 

 considering the skeleton, vertebrae and vertebral column, the skull, 

 with finally the dermal bones, in the different Piscine orders, our 

 author enters learnedly and largely into the determination of the 

 homologies or structural relations of the several parts of the skeleton 

 in Fish, when contrasted in the different members of that class or 

 those belonging to the other great divisions of the Vertebrate series 

 But let us preface in our author's own words the definition and 

 scope of the term homology as applied in the present, and to be 



