Sept. 7, 1S82] 



NA TURE 



45i 



we see here both the continuity of instinct with reflex 

 action and the constant opposition that there is between 

 mechanical quasi-mental action and free intelligence. Cm 

 the one hand the organism tends to become excessively 

 specialised by the development of instincts under the 

 influence of natural selection and by the formation of 

 habits ; on the other hand rational processes are constantly 

 being applied to slightly different material, thus becoming 

 more varied, and instincts when they become too complex 

 are partially disorganised and contribute their share to 

 the activity of the free intelligence. Thus, starting with 

 a lowly organised animal having the beginnings of intel- 

 ligence and reflex action, that is, having the germs of the 

 mental and quasi-mental processes of the higher animals, 

 we observe from this point onwards both a process of 

 development of each kind of action along its own line and 

 a process of transformation of each kind of action into 

 the other. 



In some ancient civilised societies of men, habits which 

 were originally special applications of reason to particular 

 ends have encroached to such an extent on the free intel- 

 ligence that almost the whole of life has become mecha- 

 nical routine. If the specialising tendency can go so far 

 in the case of men, may we not expect to find animals 

 rather high in the zoological scale (perhaps some species 

 of insects) in which all the mental activity has passed 

 into the form of instinctive processes? The comple- 

 mentary problem to that of finding evidences ofintell- 

 gence in the lowest animals would be that of finding evi- 

 dences of the absence of intelligence in the higher animals. 

 In discussing ants Dr. Romanes remarks that some species 

 do not seem to have general intelligence in proportion to the 

 complexity of their instincts, though " other species . . . 

 appear to be as remarkable in this respect as they are in 

 respect of their instinctive adjustments" (p. 127). But 

 if there is a constant struggle between instinct and intel- 

 ligence, an animal in which instincts have been fixed so 

 rapidly that all the plastic intelligence has been absorbed 

 in forming them is quite possible, and might be found 

 perhaps among insects. Such an organism would be a 

 realisation of the idea of Descartes that animals are 

 unconscious automata. T. Whittaker 



D/ILTONS "HUMAN PHYSIOLOGY" 



A Treatise on Human Physiology, designed for the Use of 

 Students and Practitioners of Medicine. By John C. 

 Dalton, M.D., Professor of Physiology and Hygiene in 

 the College of Physicians and Surgeons, New York. 

 7th Edition. (London : J. and A. Churchill, 1882.) 



THE seventh edition of this excellent work shows on 

 almost every page that the author has submitted 

 the previous edition to careful revision, with the result of 

 producing a much better book in every respect. State- 

 ments are made more concisely and to the point ; irrele- 

 vant or useless illustrations are suppressed ; redundant 

 sentences have been clipped and pruned till they express 

 their meaning in the shortest form. Further, the arrange- 

 ment of the book has been much improved. In the 6th 

 edition, Dr. Dalton discussed the subject under the heads 

 of "Nutrition," "The Nervous System," and " Repro- 

 duction," whilst in the present edition he has subdivided 



the first section into " Physiological Chemistry " and 

 '■ Nutrition," properly so called. This arrangement has 

 enabled him to describe more fully the chemical com- 

 position of proximate principles and to arrange the facts 

 in a more natural order. As a matter of logical arrange- 

 ment, it is doubtful how far Dr. Dalton is justified in 

 treating of the Bile under " Digestion," and the Glyco- 

 genic Function of the Liver under "Absorption," but no 

 doubt he has felt the difficulty experienced by those who 

 have been obliged to deliver a systematic course of lec- 

 tures on physiology as to the natural position of those 

 important functions. At what point do they come in, if 

 it be the object of the teacher to describe facts in natural 

 sequence and in such a way as to help the student in 

 grasping an idea of the entire mechanism ? In the 

 digestive process, the bile plays a comparatively unim- 

 portant part whilst the production of glycogen by the 

 liver has little to do with absorption. Still both of these 

 processes have a natural relation to the great functions 

 under which Dr. Dalton has placed them, and an author 

 may be excused for arranging them as he has done, on 

 the ground that it is impossible for any one, with our 

 present views of nutrition, to state precisely under what 

 head, in any systematic treatise, these functions should 

 be described. 



In discussing the "Nervous System," Dr. Dalton has 

 judiciously incorporated the facts brought to light by 

 recent investigators. Thus we have a careful description 

 of the physiological anatomy of the cerebral hemispheres 

 and associated ganglia, and an account of the experi- 

 mental evidence supplied by Fritsch and Hitzig, Ferrier, 

 Schiff, Hermann, and Carville and Duret. In particular, 

 prominence is given to the attempts of Ferrier and others 

 to determine special centres for sensory perceptions, and 

 to what may be called the " check " experiments of the 

 New York Society of Neurology and Electrotology. Less 

 importance is justly given to the results reached by the 

 rough method of extirpation followed by Flourens and 

 many others. Not a few still doubt the view that there 

 are portions of the cerebral convolutions devoted to 

 special motor or sensory functions, but the student will 

 find in Dr. Dalton's pages a very clear exposition of the 

 results of modern investigation. 



The chapter on the " Senses " is clear and intelligible 

 so far as it goes. It does not pretend to give an account 

 of the almost innumerable phenomena of the senses, but 

 it gives a fair representation of the more common pheno- 

 mena, whilst it is suggestive and critical. The account 

 of the mechanism of accommodation is meagre and might 

 be much improved. No account is given of any theory 

 of colour- perception. The account of the auditory 

 mechanism is excellent, and the author is extremelv 

 careful in discussing the attempts made to explain the 

 organ of Corti. 



The special feature of this book, in all editions, is the 

 prominence given to the function of reproduction, and we 

 may add that no text-book of a general character gives so 

 full and explicit an account of this department. Here, as 

 elsewhere, the author has endeavoured to be a teacher, 

 and has aimed not so much at giving a detailed account 

 of all the steps of the process as at presenting the subject 

 in a form easy of comprehension. Thus whilst it might 

 be possible to point out statements slightly erroneous or 



