April 15, 1880] 



NATURE 



559 



protoplasm of animals and the material which they break 

 down into secretions, such as the components of bile, or 

 such as the hydrochloric and sulphuric acid of other glands. 

 But still more important are the examples of elaboration 

 and synthesis presented by some of the lowest organisms- 

 Without chlorophyll, or, as far as we have any ground for 

 conclusion, any such intermediary, the protoplasm of the 

 Bacteria acts upon ammonium acetate so as to build up 

 carbon, nitrogen, hydrogen, and oxygen into an album- 

 inoid compound like itself. Such action appears to be the 

 specialty of protoplasm, for even when a share of the work 

 is attributed in the green plant to the green pigment 

 chlorophyll, yet we have to come back to protoplasm to 

 finish the job and _do the really difficult feat of combining 

 carbo-hydrates and ammonia. By dismissing chlorophyll 

 from the operation altogether we do not add materially 

 to the capricious many-sidedness of protoplasm. Here it 

 can take carbon from carbonic acid and nitrogen from 

 ammonia, there it can do with nothing less than an acetate, 

 there again it must have a tartrate at least, and in a fourth 

 example it perishes without albumens. 



If the green pigment has been misrepresented in the 

 foregoing indictment, and if it really is something more 

 than a screen for protoplasm, its character must be re- 

 established by direct demonstration of its capabilities. 

 The facts, as at present in evidence, look very much 

 indeed as though chlorophyll had been assigned a position 

 of unmerited dignitv. 1 E. RAY LANKESTER 



HANDBOOK OF BOTAXY 

 Handbuch der Bolanik. Bearbeitet und herausgegeben 

 von Dr. X. J. C. Midler, Professor in Miinden. Erster 

 Band, Erster Theil. Anatomie und Physiologie der 

 Gewachse. (Heidelberg, 18S0 : Carl Winter's Uni- 

 versittiubuchhandlung.) 



THE volume before us is the first of a work which is 

 to treat of all the departments of the science of 

 botany. In his preface Prof. Midler explains that he has 

 been led to undertake this very serious task by the con- 

 viction that unity of design is the first essential in an 

 educational work such as this is to be, and that this unity 

 cannot be attained unless all the parts of it come from the 

 same hand. Possibly his estimate of the value of this 

 unity may be correct, but it must not be forgotten that 

 the division of a labour such as this secures one very im- 

 portant advantage, namely, the complete treatment of 

 each of the separate parts, and this may after all be quite 

 as important as the unity of design. 



These considerations naturally recall to memory the 

 handbook which was planned on so magnificent a scale 

 by Hofmeister. That work is still unfinished, and long 

 periods of time intervened between the publication of 

 volumes of it by the different authors, so that, as it is, 

 the work necessarily exhibits but little unity of design, 

 and must therefore, from Prof. Midler's point of view, 

 possess comparatively little educational merit. As a 



' Mr. Vines suggests that if Pringsheim's view be correct, then it might 

 be possible by aid of an artificial chlorophyll screen to excite the protoplasm 

 of fungi or even of animals to the decomposition of carbonic acid. This 

 te unlikely on account of the definitely characteristic chemical 

 activities acquired by protoplasm in different organisms. But it certainly 

 would be worth whue trying the experiment with an etiolated green 



rtificial chlorophyll 



The experiment would be 



matter of fact, however, the deficient unity is hardly 

 noticed, for the parts are so complete in themselves that 

 they can stand alone, and are of permanent value as 

 books of reference. 



We will now proceed to form an estimate of the suc- 

 cess which has attended Prof. Midler in the execution of 

 the first part of his plan. In this volume he treats more 

 especially of the physiology of plants, giving also 

 some account of their coarser anatomy, and he does so 

 with so much detail that he fills more than six hundred 

 pages. It will perhaps be well to defer any remarks 

 upon the latter subject until it has been treated, as Prof. 

 MiilL-r promises, in a more complete manner in subse- 

 quent volumes. 



Witli regard to physiology, then, it must be admitted 

 that Prof. Midler's work is an elaborate one, and that it 

 gives evidence of much labour and thought ; but yet the 

 result cannot be regarded as other than unsatisfactory. 

 It contains a great deal of information, some of it of a 

 very' recondite description, but it is not arranged in a 

 clear and logical manner so that the student can rradily 

 grasp the facts and appreciate their mutual relations. 

 There is a want of proportion or perspective about it, 

 and the result is that the fundamental facts do not stand 

 out clearly from those of secondary importance. The 

 mode of stating the facts is not always all that could be 

 desired. On p. 1, for instance, protoplasm is spoken of 

 as being fluid {fliissig), a mode of describing its consis- 

 tence which is generally considered to be inaccurate. But 

 the most serious defect in the book is the want of definite 

 statements of the conditions under which the more im- 

 portant vital phenomena take place. There is a sort of 

 vagueness about Prof. Midler's account of these which 

 will prove distressing to any student who reads his book. 

 For example, let us take the [discussion of the mode of 

 growth in surface of the cell-wall. On p. 100 there is a 

 very brief statement of the theory of growth by intus- 

 susception ; on p. 146 there is an account of Nsegeli's 

 theory of the structure of the cell-wall ; but when we 

 turn to p. 170, where the account of the actual growth 

 of the cell-wall is given, no reference is made to either of 

 these theories, which are generally regarded as being of 

 the first importance in explaining the process of growth. 

 Then as to the turgid condition of the growing cell : this 

 is certainly mentioned on p. 170 and on p. 193, but no 

 hint is given of the means by which this condition is 

 produced and maintained, or of its significance in the 

 process of growth. It is evident that a student would 

 have considerable difficulty in obtaining anything like a 

 clear idea of the mode of growth in surface of a cell- wall 

 from Prof. Midler's account of it. 



Again, there is no clear distinction made, in Prof. 

 Midler's account of the circulation of liquils in the plant, 

 between the slow movement of solutions of nutritious 

 substances and the rapid movement of water in connec- 

 tion with the process of transpiration ; and the paths along 

 which the liquids travel in these two movements are by 

 no means clearly traced. The recent important researches 

 of Sachs and of von Hbhnel on this subject appear to 

 have been overlooked. 



Further, in discussing the decomposition of carbonic 

 acid by chlorophyll under the influence of sunlight, Prof. 

 Midler makes no clear statement as to which of the 



