March 28, 1889] 



NATURE 



507 



PLANT LIFE. 

 PJlanzenlebcn. Von Anton Kernervon Marilaun. Erster 

 liand. Gestalt und Leben der Pflanze. (Leipzig, 1887.) 

 'T^^'HIS is a book which deserves the warmest welcome 

 i- from all lovers of plants. To give a general and 

 at the same time a full and accurate survey of the natural 

 history of plants, is at the present time a task of immense 

 difficulty, and one which very few botanists could under- 

 take with any hope of success. The task is daily becom- 

 ing more difficult, as new additions are made to the 

 already huge accumulation of facts, while its efficient 

 performance is now a matter of more importance than 

 ever, if botany is to be saved from becoming a close 

 science, for specialists only. It may be said at once that 

 the author has done his work with remarkable success. 

 The book is a large one ; only the first volume is before 

 us, and this contains 734 large octavo pages. Yet it is 

 scarcely an exaggeration to say that there is not a dull 

 page from beginning to end of the bulky volume. On 

 the other hand, inaccuracies are met with here and there, 

 and some of these are serious, but the general excellence 

 of the book is but little affected by these faults. 



Before entering on a fuller account of the text, we must 

 say a word about the illustrations, which are among the 

 greatest merits of the book. In the text are 553 figures, 

 many of which are pictures of great beauty. In addition 

 to these there are twenty coloured plates, the first of 

 which is histological, while all the rest represent various 

 aspects of vegetation, both terrestrial and aquatic, in 

 different parts of the world. Many of these plates are 

 accompanied by an outline tracing of the individual plants 

 shown, each figure on the tracing bearing a reference 

 number, while the names are given below. This is an 

 excellent plan (already frequently employed by French 

 zoologists), and adds much to the practical value of the 

 plates. 



We will endeavour to give some idea of the plan of the 

 work so far as it extends at present, but only a very 

 cursory view will be possible. The present volume may 

 be said to deal with general organography and physiology, 

 especially of the vegetative organs. Comparatively little 

 space is given to the organs of reproduction, which will 

 no doubt receive full attention in the second volume, 

 dealing with special morphology. 



The introduction is headed, "The Investigation of the 

 Vegetable World in Ancient and Modern Times." It 

 contains a general view of the history of the science. 

 This is very well done, and is calculated to rouse the 

 interest of the reader. 



Chapter I. is on the living substance of plants 

 ("Das Lebendige in der Pflanze"), and may be de- 

 scribed as an outline sketch of histology. The discovery 

 of the cellular structure of plants by the naturalists of 

 the seventeenth century is first narrated, and some of 

 Nehemiah Crew's classical figures are here reproduced. 

 Protoplasm and its movements next receive attention, 

 and in this section there is some room for criticism. 

 Thus the well-known motile granules of Closterium are 

 wrongly described as being embedded in the protoplasm 

 (p. 34), and the difficult question of the movements of 

 Diatoms will scarcely find its solution in the theory here 

 advocated, according to which Diatoms move in much 



the same way as mussels ! In the following section the 

 nucleus and chlorophyll-bodies are treated too much as if 

 they were of the nature of secretions from the protoplasm, 

 like oil-drops or crystals, whereas in all cases of which 

 we have any definite knowledge they originate solely by 

 the division of pre-existing bodies of the same kind. 

 Probably, as regards the chlorophyll-corpuscles, the author 

 wrote under the influence of the somewhat doubtful ob- 

 servations of Mikosch. The division of the nucleus is 

 described by the author later on in the volume, but it 

 would have been well to lay more stress on the process 

 in this place. The remarks on the continuity of proto- 

 plasm through the cell-wall are acute and interesting, 

 but it is rashly assumed, in opposition to the most trust- 

 worthy investigations on sieve-tubes, that this continuity 

 exists from the first origin of the cell-wall. The author's 

 attempt to identify the intercellular protoplasmic threads 

 with the achromatin fibrils formed during cell-division 

 is equally open to criticism. 



The second chapter (pp. 51-246) deals with the absorp- 

 tion of food. This is a striking chapter, and presents in 

 a very attractive manner a part of the science which is too 

 often made to appear excessively dry. Attention may be 

 called to one or two especially good sections, such as 

 those on the nutrition of water-plants and of " stone- 

 plants." The remarks on the correlation between the 

 position of the leaves and the distribution of the roots, as 

 affecting the water-supply of the plant, are of great interest, 

 and are illustrated by excellent figures (pp. 85-92). Sapro- 

 phytes, insectivorous plants, and parasites are all fully 

 and vividly described. As regards the parasites especially, 

 the account here given is the best general one with which 

 we are acquainted, and the illustrations are as good as 

 the text. Lathraea is reckoned among insectivorous plants 

 as well as among parasites, and the author's peculiar 

 theory as to the nutrition of this plant by means of alleged 

 protoplasmic fibrils projecting from the surface of its 

 glandular hairs, is again brought forward (p. 128). This 

 view must now be regarded as more than doubtful. 

 The section on the absorption of water (pp. 199-223), is 

 perhaps the least satisfactory in the book. The most 

 heterogeneous organs, extra-floral nectaries and chalk- 

 glands among the rest, are classed, on the slightest 

 possible grounds, among organs for the absorption of 

 water, and thus their true functions come to be over- 

 looked. It is difficult to understand how so forced and 

 fanciful a theory can be maintained by any good observer. 

 The short section on symbiosis is clear and satisfactory, 

 and Frank's views on the vexed " Mycorrhiza " question 

 are well put forward. 



Chapter III. (pp. 247-343) is on the conduction of 

 food. Root-pressure, transpiration, and the ascent of 

 water through the wood are well discussed, Godlewski's 

 views on the last-mentioned subject being provisionally 

 adopted. The whole question is treated as clearly as is 

 possible, 'in the present state of our knowledge, in a 

 populai* book. The detailed account of the structure of 

 leaves as affecting transpiration is particularly good, 

 and the illustrations here deserve the highest praise. 

 The concluding sections of this chapter are concerned 

 with the fall of the leaf, the relation of transpiring surface 

 to water-conducting tissues, and the conduction of gaseous 

 food-substances. 



