122 



NA TURE 



[June 6, 1907 



ating in bronze, and their rudimentary writing), 

 while it also absorbed certain elements from the 

 primitive Neolithic civilisation of the original 

 " Ligurians " of the Tiber valley. Finally (lantae 

 rnoXis erat Romanam condere gentem), there came 

 the Etruscans, at about the same date as the Umbro- 

 Sabellians. The Etruscans, according to Prof. 

 Modestov, who accepts, and fortifies by archaeological 

 evidence, the testimony of Herodotus, were a people 

 from .Asia Minor, who came bj" sea to Tuscany, bring- 

 ing, inter alia, Eastern methods of divination which 

 they had borrowed through the Hittites from Chaldasa. 

 To corroborate this view, Prof. Modestov alleges the 

 conclusions of a Danish scholar, who seeks to con- 

 nect the mysterious Etruscan language with the 

 dialects of the southern Caucasus. Here Prof. 

 Modestov seems somewhat inconsistent, for while he 

 compares the archjeological relics of the Etruscans 

 with those of south-western Asia Minor, he compares 

 their language with the dialects of the north- 

 east. 



We should be ungrateful if we did not mention the 

 many illustrations, for the most part original, with 

 which the author has ornamented his book and sought 

 to aid his readers. The Etruscan illustrations are 

 particularly interesting. 



Ernest B.-^rker. 



THE FUNCTIONS OF THE BRAIN AND 

 SPINAL CORD. 

 The Integrative Action of the Nervous System. By 

 Dr. C. S. Sherrington, F.R.S. Pp. xvi + 411. 

 (London: Archibald Constable and Co., Ltd., 1906.) 

 Price 16s. net. 



THE unravelling of the arrangement and complica- 

 tions of the nervous system has always been of 

 great interest, not only to physiologists, but also to 

 mankind in general. The specially human attributes 

 which distinguish our species from the rest of the 

 Mammalia have at least an intimate connection with 

 the superior developrnent of the central nervous 

 system, and we have therefore a peculiar interest in 

 tracing the methods by which this complexity is of 

 advantage to the individual. 



The central idea of the book under review is the 

 action of the nervous system in connecting the various 

 cells composing the body into one individual, as dis- 

 tinguished from a mere collection of separate items. 

 While there are other agencies that work to this end, 

 mechanical as well as chemical, still the nervous 

 system is preeminently effective in this respect from 

 the delicacy and speed with which the intercommuni- 

 cation is effected. The unit reaction, to which all the 

 complex phenomena of nervous activity are referable, 

 is recognised to be the " simple reflex action." 



The recognition of this definite unit, in place of 

 the vague generalities too often quoted, marks the 

 first important step in the study of the subject. 



Prof. Sherrington then goes on to show that the 

 anatomical basis underlying this siinple reflex con- 

 sists of three parts : — (i) the receptor, the sensitive 

 lorgan which receives the impression ; (2) the foii- 

 NO. 1962, vol,. 76] 



diictor; (3) the effector, the organ which effects the 

 reflex act. 



The various details of the apparatus are then con- 

 sidered. By an arrangement of this kind the 

 threshold is lowered for one kind of stimulus and 

 heightened for others, so that the reflex becomes 

 selective. The phenomena called out by these stimuli 

 are then considered, namely, the irreversibility of the 

 direction of the impulse, the long latent period, and 

 the rhythm of the action. By the method of " suc- 

 cessive degeneration " it is possible to examine the 

 conductor apparatus, and the conclusion is arrived at 

 that the simple reflex arc is at least disynaptic, 

 that is, composed of three separate neurones as a 

 minimum, that the " effector " part of the arc is 

 a " final common path " for all the reflexes using the 

 particular end organ attached to it, and that some- 

 where in the " conductor " (the part of the arc con- 

 necting receptor and effector) there is some mechanism 

 which gives a refractory phase. The importance of 

 this is seen when such a phenomenon as the scratch 

 reflex is examined, as this consists of a rhythmic 

 series of movements the rate of which is governed 

 by the purpose for which the reflex acts, and not by 

 the rapidity of the successive stimuli. Further, as 

 such a reflex is a coordinated action, there must be 

 rhythmic inhibition of a series of muscles as well a? 

 rhythmic contraction of the opposing set, and by a 

 series of well-devised experiments and careful con- 

 sideration of the results the author again makes an 

 important advance. This becomes more evident when 

 the next chapter of the story is considered, namely, 

 the compounding of reflexes, and the method by 

 which one reflex becomes prepotent over another 

 which would use antagonistic muscles. 



The limited space at a reviewer's disposal will no' 

 permit the further description of Prof. Sherrington's 

 account of the functions of the cerebral cortex and the 

 very ingenious experiments on sensual fusion, but it 

 will be found that the later chapters of the book 

 possess the same wealth of information and lucid 

 reasoning as the earlier. The only criticism that 

 might be gently urged is that occasionally the 

 language in which the reasoning is conveyed becomes 

 nearly as complicated and abstruse as the subject- 

 matter of the discourse. Sometimes, however, this 

 recondite phrasing hides gems of humour as well as 

 knowledge, as in the sentence on p. 317 : — 



" Into that sequestered nook the organism by 

 appropriate reactions gathers morsels of environ- 

 mental material whence by chemical action and by 

 absorption it draws nutriment," 



which by careful examination of the context appears 

 to mean " Tommv ate a piece of cake ! ! ! " 



But, jesting apart, we have in this book the most 

 valuable contribution to the comprehension of the 

 functions of the nervous system that has appeared 

 up to the present time, not only from the records of 

 the experiments quoted, but also from the logical and 

 orderly way in which the due inferences from the 

 experiments are put forward, and the volume stands 

 out as a landmark in our knowledge of the subject. 



