August 13, 1896] 



A^A rURE 



541 



at all in tliis connection, should be restricted to the 

 nerve-fibre process of the cell, for which they prefer the 

 longer term iiciira.xon ' Of course, as every one knows, 

 our authors, in taking this course, are merely following 

 the lead of a certain eminent (".crman anatomist, it being a 

 fashion with American scientific writers (except a few who 

 prefer a sort of scientific \'olapuk) to follow pretty blindly 

 ail ("lerman scientific leads in the matter of nomenclature, 

 and this even to the extent of bodily adopting actual 

 German words into a language which can already find 

 two or three synonyms for almost any word it may be 

 desired to translate. No doubt many English authors 

 are also to blame in this respect, but the fact is none the 

 less to be deplored. And how can the average student 

 be expected to understand the homologies of the nerve- 

 cell if he is taught that he is not to call this particular 

 unit a cell, like all the other units in the body, but is to 

 restrict the term to a part of it only, for no other reason 

 than the fact that when we were more steeped in ignor- 

 ance of the structure of the nervous system than we are at 

 present, that particular part of the nerve-cell was sup- 

 posed to represent the whole I 



Nevertheless, it may be freely admitted, in spite of the 

 above criticisms, that many of the reproductions are 

 extremely well done, and may with advantage be care- 

 fully studied by those who have not the opportunity of 

 preparing for themselves specimens of like nature to 

 those depicted. E. \. Schafer. 



OUR BOOK SHELF. 



Flora der Oslfricsischcn Inseht [einschlicsslich dcr InscI 

 U'n/ti,'iTot>i;}. \'on Prof. Dr. F. Buchenau. Dritte 

 umgearbeitcte .Auflage. Small 8vo, pp. 205. (Leipzig : 

 Wilhelm Engelmann, 1896.) 

 Dr. Buchenau is well-known as a botanical author for 

 the simplicity and lucidity or his style, and the thorough- 

 ness with which he treats his subjects ; and this little 

 book is no exception to his usual work. Indeed, it is a 

 model of what a local Flora should be, in striking con- 

 trast to the bulky barrenness of some of our English 

 county Floras. It will easily go into the breast-pocket of 

 a coat, and, as it contains descriptions and other in- 

 formation, it may be used, and be useful, in the field. 

 The flora of the Frisian Islands is, on account of their 

 situation, of great interest ; and Dr. Buchenau has 

 worked out its features, composition and peculiarities, 

 with a full appreciation of its interest. An introductory 

 chapter of some twenty-eight pages is a summary of the 

 authors observations on various points ; observations 

 which have been published in full elsewhere, to which 

 leferences are given. The paragraph on sand-binding 

 plants is valuable. With regard to the flora as a whole, 

 two principal points come under consideration, namely, 

 its composition and origin. Taking into account the area, 

 but more especially the slight elevation, the absence of 

 trees, and almost so of shrubs, the flora is a comparatively 

 rich one, and includes a number of species we should 

 hardly expect to find. Dr. Buchenau says that the 

 commonly accepted idea that the most interesting plants 

 of the islands are relatively recent immigrants from the 

 mamland of North-west Germany, will not bear investi- 

 gation. " The most striking plants of the islands — Liparis 

 La'sclu\ Gyinnadenia conopsca, Kpipactis latifolia, 

 Parnassia palustris, &c , are either wanting or ex- 

 ceedingly rare in East Friesland. They are only met 



NO. 1398, VOL. 54] 



with, by degrees, much further south. It is, therefore, 

 inconceivable that they have migrated from the mainland 

 in recent times, and assembled in these islands. The 

 more probable explanation is that these plants are the 

 remains of the old diluvial flora which from various 

 causes have survived in the islands, though they have 

 disappeared from the nearest mainland." I may add that 

 Dr. Buchenau has made a special point of drawing up 

 his descriptions, which are short and clear, from local 

 forms. W. BOTTINC; Hemslev. 



A Text -hook of Physical Exercises adapted/or the Use of 

 Elementary Schools. By Dr. A. H. Carter and Samuel 

 Bott. Pp. X + 168. (Macmillan and Co., Ltd., 1896.) 



This book calls for notice in Nature because the exer- 

 cises in it are founded upon a physiological basis. In a 

 lucid introduction, Dr. Carter deals with "The Physiology 

 of Exercise," and what he says should be read and 

 digested by every teacher who has to do with the 

 physical training of children. A knowledge of the struc- 

 ture and functions of muscular tissue is essential in order 

 to fully appreciate the value of different exercises. For 

 to know the physiological effects of exercise, the cause of 

 fatigue, breathlessness, the nature of muscular stiffness, 

 the reason why rest is necessary for the renewal of 

 reserve force and the relief of muscular pams, is to pos- 

 sess the ability to judge the suitability of this or that 

 exercise for the purpose of physical development. 



Physical exercises have been carried out in the schools 

 of the Birmingham School Board for the last ten years, 

 and Mr. Bott, who organised and directs them, has, there- 

 fore, had ample opportunity of knowing the practical 

 conditions of the exercises he describes. It is difficult 

 to give clear and practicable instructions for the 

 successful performance of such exercises as those with 

 which the book deals, but, by means of concise text 

 and numerous 'illustrations, this has been satisfactorily 

 done. These instructions, and Dr. Carter's admirable 

 lesson in physiology, will equip teachers with all they 

 need know in order to carry out a sensible and syste- 

 matic course of physical training for children. 



Der Lichisinn augenloscr Tiere. By Dr. Wilibald A. 

 Nagel. Pp. 120. (Jena: G. Fischer, 1896.) 



H.\LK of this interesting study is taken up by a paper on 

 " Seeing without Eyes," in which the author considers 

 the general question of sensitiveness to light, with illus- 

 trations from his own researches. In the second half 

 these researches are described, and some special questions 

 more fully discussed. The author's own observations 

 were made chiefly on lamellibranchs and gasteropods, 

 and showed a high degree of sensitiveness to light in the 

 absence of anything like a visual organ. He found that 

 some molluscs reacted especially to diminution, others to 

 increase of light, and that this difference was correlated 

 with other characters ; those molluscs with soft shells, 

 which bury themselves in the sand, reacted strongly to 

 light, while those with hard shells responded more to 

 shade. He found the highest degree of sensitiveness to 

 light in Psammodia ; and it is interesting to note, in 

 relation to the common view as to the connection between 

 sensitiveness to light and pigment, that the impregnated 

 siphons of this mollusc were highly sensitive. Another 

 interesting point investigated was the influence of 

 repetition of a light stimulus. An oyster or mussel which 

 has reacted to a shadow will react much less strongly, or 

 not at all, to a second stimulus, even if much more 

 intense, and does not recover its previous degree of 

 excitability till more than an hour has elapsed. The 

 book concludes with a full bibliography. 



