554 



NA TURE 



[April i r, 18915 



certain external causes or under exceptional physiological 

 conditions ; and, moreover, that in certain invertebrates 

 the constant condition of the muscles corresponds rather 

 to the modified than to the ordinary state of the muscles 

 of the higher animals. If we proceeded to inquire in 

 what this modification consists, Biedermann's answer 

 would be that it may be distinguished in all cases by its 

 electrical concomitants— all "modified" parts being 

 relatively negative to similar parts which are unmodified. 

 Thus when the adductor muscle of the nipper of the 

 crayfish, which is normally in a state which resembles the 

 " modified'' state of an ordinary muscle, passes into a con- 

 dition corresponding to that which is normally present 

 in the muscles of the frog, a change takes place in the 

 electrical relations of the structure of such a character 

 that the sign of the electrical response to stimula- 

 tion is reversed ; it becomes negative instead of posi- 

 tive. Comparing these facts with others relating to 

 vision, with the processes of secretion, and with other 

 processes under the immediate control of the ner- 

 vous system, one is encouraged in the hope that 

 the relations between ana and cata, between rest and 

 activity, between restoration and exhaustion, between 

 integrity and hurt, will eventually be linked together 

 by their electrical concomitants, and that by these 

 characters it may be possible to ascertain with exactitude 

 and certainty in how far these various antagonisms may 

 be referred to a common principle. 



.Space will not allow us to give an account of the last 

 chapter in Prof. Biedermann's book, which contains 

 much that is new and important relating to the electro- 

 motive phenomena of secreting cells. Enough has been 

 said to satisfy the physiological reader that the book is 

 one which will have permanent value. It is, moreover, 

 readable. The author tells us in his preface that he has 

 done his best to get rid of " lehrbuchmiissige Trocken- 

 heit." We think that he has fairly succeeded. 



J. BuRDON Sanderson. 



THE PHYSIOLOGY OF PLANTS. 



A Popular Treatise on the Physiology oj Plants, for the 

 use of Gardeners, or for Students of Horticulture and 

 of Agriculture. By Dr. Paul Sorauer, Director of the 

 Experimental Station at the Royal Pomological Insti- 

 tute in Proskau (Silesia). Translated by F. E. Weiss, 

 H.Sc, F.L.S., Professor of Botany at the Owens Col- 

 lege, Manchester. (London : Longmans, 1895.) 



OF all the sections into which the teacher of botany 

 must divide his subject, perhaps the most difficult 

 for him to deal with is that of vegetable physiology. No 

 adequate elementary text-book has hitherto existed in 

 English, the classical works of Sachs and Vines being, 

 by their very completeness, too bulky and too fall of 

 detail for the student who is beginning the study of the 

 subject. The work of Dr. Sorauer is intended to supply 

 this deficiency. It is written especially for those whose 

 interest in the matter is a practical one, and it deals, 

 consequently, miinly with those ciuestions which arc of 

 interest to the horticulturist as bearing on the problems 

 of cultivation. Approaching the matter, however, from 

 this side only, the book, as a work on physiology, 

 NO. 1328, VOL. 51] 



to a certain extent comes short of what is needed, 

 as many important sections of the subject are left 

 untouched. 



The author deals almost entirely with the problems of 

 nutrition and their bearings on the details of horti- 

 cultural practice. -Vt the outset he strikes a rather 

 heavy blow at what has hitherto been, unfortunately, 

 the pron'.inent idea of most agriculturists and horti- 

 culturists as to what constitutes the scientific side 

 of agriculture. The latter has been held to embrace 

 little or nothing beyond the chemistry of the soil, 

 and everything not directly connected with this has 

 been pushed into a secondary position, the metabolism 

 of the plant ani the chemical changes of its constituents 

 being generally very superficially treated and held of 

 not very great interest. It certainly seems strange that 

 those who have been engaged especially in the cultivation 

 of sensitive organisms under very varied and rapidly 

 changing conditions should have given so little atten- 

 tion to the physiological peculiarities which these organ- 

 isms present, and to their power of availing themselves 

 of the various advantages that their environment offers 

 to them. Dr. Sorauer, at the outset, strikes the right 

 line when he points out that the chemistry of the soil, im- 

 portant as it is, plays only a secondary part in the de- 

 velopment of the various plants which that soil supports, 

 and directs his readers' thoughts chiefly to the problems 

 of nutrition which the plant itself olTers for consideration, 

 showing that it is the business of the cultivator to 

 endeavour to guide the natural development of the 

 plant towards the special ends which are the needs of 

 horticulture. 



This idea, put prominently forward in the opening 

 chapters, runs throughout the whole of the book. In 

 developing it, the interactions between the soil and the 

 plant, or between the plant and the atmosphere, are kept 

 in the foreground, so that the gardener may realise tli.u 

 he is face to face with an actual struggle that is going on 

 continuously between the organism and its environment, 

 and that he is working to secure that in this contest those 

 conditions of the latter maybe secured which are most 

 favourable to the success of the organism, and hence 1 1 

 its most complete development. 



In the earlier chapters of the book, the author treats 

 successively of the several members of the plant, the 

 root, stem, leaf, tlower, and fruit. Without going very 

 deeply into their anatomical structure, he explains it 

 sufficiently for the student to get an adequate compre- 

 hension of the duties or functions which are especially 

 discharged by each. Again his mode of procedure is 

 sound, as it is only function that gives the clue to the 

 right interpretation of structure. The method, as 

 carried out by Dr. Sorauer, is, however, open to a little 

 objection, as it has led him rather to push too far the idea 

 of the several members of the plant living for themselves, 

 and to relegate a little to the background that of the 

 plant being an organic whole, differentiated in dilTerent 

 directions for the carrying out of dilTcrent functions. 

 Thus the leaf is spoken of as passing oil' into the vascular 

 bundles of the axis only such materials as it cannot at 

 once employ for its own growth, leading the student 

 probably to the conception that the latter problem is for 

 the leaf the primary one, and that the nutrition of the 



