March 9, 191 1] 



NATURE 



41 



from it we learn what Miinsterberg, Ribot, Jastrow, 

 Prince, Janet and Bernard Hart mean by the sub- 

 ccnscious. That such a work serves a useful purpose 

 may be gathered from the fact that, as the master of 

 the'symposium states in his introduction, there are six 

 ; recognised meanings of "the subconscious": — 



(i) That portion of. consciousness which for the 

 moment is outside the field of attention. 



(2) Split-off or dissociated ideas, such as automatic 

 writing. 



(3) A subliminal, secondary, subconscious "self" 

 j constituted and elaborated from such dissociated ideas. 

 \ (4) A combination of dissociated and forgotten 

 ; ideas. 



(5) The subliminal reservoir of consciousness from 

 I which ideas are drawn into phenomenal conscious- 

 ' ness. 



(6) Certain neural processes unaccompanied by any 

 t mentation whatsoever. 



Most of the writers take the view that subconscious 

 (phenomena are physiological and not psychical pro- 

 cesses, the underlying reason in all being that they 

 are not memories, ideas or anything" else of which 

 * mentation is composed. 



\ Janet, of course, limits the subconscious to such 

 abnormal states as are encountered in hysteria and 

 psvchasthenia, and Bernard Hart considers that the 

 marginal elements of phenomenal consciousness (the 

 ■subconscious of Stout), dissociated portions of pheno- 

 'menal consciousness (the co-conscious of Morton 

 Prince and the subconscious of Janet) and the non- 

 phenomenal conceptual unconscious of Freud all form 

 part of the material of psycholojrv and not of physio- 

 logy. It need scarcely be said that a symposium bv 

 'such writers is above criticism ; they criticise each 

 other. 



Mikroskopische Untersuchungen iiber die Ubereinsttm- 

 munfl in der Struktur iind dem Wachstume der Tiere 

 and Pflanzen. By Dr. T. Schwann. Edited by F. 

 Hunseler. Pp. 242 4- iv Taf. (Leipzig: W. Engel- 

 mann, 1910.) Price 3.60 marks. 



iAr a time when the accumulation of the facts of 



animal and plant structure threatened to prevent a 



clear conception of their true value, this famous 



memoir by a distinguished pupil of Johannes Miiller 



"nverted histology into a rational branch of science. 



"Schwann, who effected this profound chang-e, based his 



ihod on development. Fie pointed out that "there 



a common principle of development for all the ele- 



. inentary parts of the organism," and in so doing 



- Founded (wnth Schleiden) the cell-theory upon which 



inodern physiology and pathology are based. The 



"ellular nature of animals and plants had already been 



monstratod, but there was no general hypothesis to 



'llifi'ate " the facts. This Schwann supplied. He 



i'>t only confirmed facts of cellular structure, but, in 



I refreshing^ly broad way, and moving with the ease 



if s^enius amongst a multiplicity of data that would 



lave bewildered a lesser mind, he broug'ht forward the 



vidence for the origin of the tissues and enunciated 



li'arly his views on the nature of life. 



To Schwann the organism is a beehive, as Huxley 



,;aid in his famous essay on this very treatise. Its 



ictivities are the expression of the mvriads of cell- 



hanfjfcs, each independent of all the rest. To 



ichwann, and almost against his better judgment, the 



ir^anism was, indeed, the product of its cells, and its 



^\\ the result of the crystallising of a "cytoblastema." 



ough in some ways we have outg^rown this essay, 



influence will probably always be felt, and when 



istology, as to-day, has become incapable of largo 



iows from the overburdeninp" load of descriptive data. 



Ij.'e realise the need of another Schwann ; let us be 

 ! NO. 2 1.^.8. VOL. 861 



! 



thankful for the physiologist who by his develop- 

 mental hypothesis put the subject-matter into a definite 

 problem and offered a feasible answer. 



Determinacion de la Latitud por la Observacion de 

 Distancias Cenitales de la Estrella Polar. By C. 

 Puente. Pp. 227. (Madrid : Observatorio Astrono- 

 mies de Madrid, 1910.) 

 This is a monograph on the method of determining 

 the latitude of a place from observations of the 

 zenith distances of Polaris, at a known time. There 

 is nothing new in this method, which proceeds on the 

 ordinary lines of developing the latitude in a series 

 of ascending powers of the polar distance, but the 

 author has put the discussion out with great clearness 

 and considered very carefully the terms that must be 

 taken into account, according to the degree of ap- 

 proximation needed, as well as the most suitable for- 

 mulae for use when Polaris is near the upper or lower 

 culmination. The methods of observing by means of 

 theodolites, the instrumental adjustments, and the 

 precautions necessary to be taken to ensure accuracy 

 are detailed with very great care, the instructions 

 being evidently intended for those who have had little 

 practice. Numerous examples are worked out by 

 different methods, and we have the ordinary curiosity 

 of a latitude determined to the hundredth of a second 

 when the microscopes read only to half seconds, and 

 the time is observed no nearer than a second. Some 

 of the results are so accordant that the ordinary 

 observer must despair of attaining a similar accuracy. 

 The greater portion of the book contains auxiliary 

 tables for accelerating the reduction. Some of these 

 have been extended from Albrecht's " Formeln und 

 Hilfstafeln fiir geographische Ortsbestimmungen." 

 and are available only within the limits of the Iberian 

 Peninsula. — The more important of the tables include 



, r 2 sin^ i/ , 2 sin"* ^/ , cos d) cos 8 ., 



values of — -. — ^, log — ; — ,f-, also ~ .— -V. , — r- where 



sin I sin I sm (S±0) 



^, (f), and 8 have the ordinary signification. 



Calculus Made Easy. Beinis, a very simplest Intro- 

 duction to those beautiful Methods of Reckoniiiii 

 which are f^enerally called by the terrifying names 

 of the Differential Calculus and the Integral Cal- 

 culus. By F.R.S. Pp. viii+178. (London: Mac- 

 millan and Co., Ltd., 19 10.) Price 2^. net. 

 The author of this little book writes as if it were the 

 first of its kind, and in encouraging his readers he 

 continually jeers at the professional mathematician in 

 what might be regarded as reckless nursery language. 

 In spite of such faults, we have no doubt that the 

 book will be useful to schoolboys who need the ideas 

 of the calculus in their study of physical science. The 

 voungf eng^ineer or the clever schoolboy will think it 

 illogical and slipshod to leave (dxY out of considera- 

 tion, as it is inconsiderable in comparison with the 

 other terms of (x + dxY, and he will say that there is 

 only a pretence in the prcwf of the differentiation of 

 .*•" ; he will probably look upon the introduction of 

 the expansion of (14- i/n)" when n is indefinitely great, 

 as not quite playing- the nursery game. 



Einfiihrung in die Biologic. Ein Hilfsbuch fiir 



hohere Lehranstalten und fiir den Selbstunterricht. 



By Dr. W. Schoenichen. Pp. viii + 215. (Leipzig: 



Quelle and Meyer, 1910.) Price 2.60 marks. 



Ir is difficult to understand to whom this little book 



is intended to appeal. It might almost be described 



as a scrap-book of illustrations, borrowed mostly 



from other text-books, and strung together with a 



minimum of letterpress. The subject-matter is treated 



from the point of view of physiolojjy rather than that 



of comparative anatomy, but there is a short section 



dealing with cells and tissues, and some extremely 



