Januaby 1, 1898.] 



KNOWLEDGE. 



21 



In Darwin's works he has the best foundation possible for 

 a study of scientific method, and above all he has planned 

 his book well and written it lucidly. 



After a brief explanation of logical processes we have 

 the following chapters, each one being discussed in 

 connection with well-chosen examples from Darwin's 

 works: — Darwin's Views of Method, Starting Points, 

 Exhaustiveness, Negative Evidence, Classification, Analogy, 

 Induction, Deduction, Unverified Deductions, Erroneous 

 Deductions, General Discussions, Logical History of the 

 Principle of Natural Selection, and Conclusion. 



We have given an idea of the scope of the book and 

 heartily recommend it, especially to those who are starting 

 out on scientific work of whatever kind. t)ur only com- 

 plaint is that the book is not larger and more exhaustive. 



BOOKS KECEIVED. 



Biirenii of American Ethnnloiji/ — Sirtefn/Ji Annual Separf. 

 (Government Printing OflSc'e, Washington.) 



The Sun's Place in Naivre. By Sir Norman Lock ver. (Macmillan.) 

 Illustrated. 12s. 



Bit Soadside and River — Gleanings from Natttre's Tields. Bv 

 H. iload Briggs. (Elliot Stoek.) Frontispiece. 8s. 6d. 



The Journals of Walter White, formerhi Assistant Secretary of 

 the Sot/al Societi/. With Preface by William White. (Chapman & 

 Hall.)' Portrait.' fis. 



Observational Astronomi/. Xew Edition. Bt Arthur Mee. 

 {Western Mail, Limited, Cardiff.) Illustrated. 29." 9d. post free. 



Modern Architecture. By Heathcote Statham. (Chapman & Hall.) 

 Illustrated. 



The Encyclop(edia of Sport. Edited by the Earl of Suffolk and 

 Berkshire, Hedley Peek, and F. G. Aflalo. Vol. I. (Lawrence & 

 BuUer.) Illustrated. 25s. 



We regret to record the death of Dr. F. A. T. Winnecke, 

 at Bonn on the 3rd December, 1807, in the sixty-third 

 year of bis age. Curiously enough, the comet which bears 

 his name, and having a period of 5-818 years, is expected 

 to return to perihelion almost at any time in the early 

 part of the present year. He was born in Hanover on 

 5th February, 1835, and received his education at Berlin. 

 After assisting Encke (Encke's comet, period 3-303 years, 

 is also expected about May of this year) at the observatory 

 there, and afterwards Argelander at Bonn, he accepted an 

 appointment in Russia, and many years of his greatest 

 scientific activity were spent at Pulkowa. In ISfis Dr. 

 Winnecke took charge of the observatory at Carlsruhe, and 

 in 1872 he was nominated Professor of Astronomy at the 

 newly founded University of Strasburg. He was elected an 

 Associate of the Royal Astronomical Society in 1863. 

 Cometary astronomy always had for him great attractions ; 

 besides the periodic comet which bears his name he found 

 several others, receiving the prize of the Vienna Academy 

 of Sciences for his cometary discoveries. 



BOTANICAL STUDIES.-I. 



VAUCHEEIA. 



By A. Vaughan Jennings, f.l.s., f.g.s. 



THE study of plants has till recent years occupied a 

 somewhat different position from that of its sister 

 sciences. When geology was rousing the interest 

 of the intellectual world by its conclusions as to 

 the history of the earth, and while zoology formed, 

 mainly, the battle-ground of the evolutionists and their 

 adversaries, botany still remained a science of the 

 collector and the classifier. Only comparatively lately has 

 it been able to take its place as a philosophic science on a 

 level with zoology. Its acquirement of this position has 

 been due to the increasing number of capable students, 



and the improvement of microscopic methods of research. 

 It is possible that a recognition of the importance of 

 microscopic study has sometimes led botanical teachers 

 too far in contrasting their work with that of the earlier 

 students of the field and the herbarium. There may be 

 room for a protest against the predominance of micro- 

 technicality, but the work of the microscope in giving 

 botany its proper position in the Ufe sciences can never be 

 seriously exaggerated. 



The discovery of the life histories of lower plants, of the 

 details of the reproductive processes in higher cryptogams, 

 and the demonstration of the relationship between them 

 and those of the flowering plants, form one of the most 

 striking chapters in the history of biological research. 



Though these results have been arrived at only by long 

 labour, by the employment of high magnification and 

 refined methods of preparation, it is yet by no means 

 impossible for the amateur microscopist to see for himself 

 a great number of the more important phenomena in 

 question in this line of investigation. It is proposed to call 

 attention to a few important types, which form, as it were, 

 landmarks in the world of plants. 



As a starting point we may select a common and easily 

 obtainable plant in which the reproductive processes 

 are simple and readily observed. The species of the 

 genus Vaucheriii form green velvet-like patches on 

 damp ground or thick felted masses of threads in ponds 

 and ditches. With a low-power pocket lens only, the 

 branched and interlacing threads can be distinctly seen, 

 and it may be observed that some carry small rounded 

 excrescences on the side, while others may be darker in 

 colour and enlarged ai the tip.* If a specimen is 

 mounted in water and examined with a low power of the 

 microscope, it will be found that the whole plant consists 

 of a cylindrical tube of protoplasm enclosed by a dehcate 

 cell wall ;t but there are no transverse walls crossing 

 the tubes. If the green colouring matter, or chlorophyll, 

 is dissolved out by soaking in alcohol, and the specimen 

 treated with iodine solution, or other suitable stain, it 

 will be found that the protoplasm contains numerous small 

 specialized portions or nuclei which are deeply coloured. ; 



The plant is thus a protoplasmic body with numerous 

 nuclei, but the division of these nuclei is not followed by 

 formation of new cell walls, and the plant remains uni- 

 cellular.? There is a wrong impression produced if we 

 speak of the higher plants as aggregations of cells, as if 

 they were so many brinks ; and the group of algas to which 

 roKt/icr/rt belongs is of special value in reminding us of 

 the fact that the cell walls are of secondary importance in 

 comparison with the protoplasm and nuclei. It is the 

 great series of the Siphonncia which includes a large number 

 of marine seaweeds often of considerable size and complex 

 structure. To it belong such varied types as the green 

 furry Coiliinn, common on the piles of our sea-coast piers ; 

 the feathery Bryopsis of our rock pools ; the polymorphic 

 Caulfrpa and the calcareous coralline-like Halinu'chi of 

 warmer climes ; and the quaint little umbrella-like 

 Acetabularia of the Mediterranean. Such variety of form 

 and wide distribution suggest a great antiquity for the 

 group, and there is little doubt that in the Eocene Dactylo- 

 pora and Oralites, and the Triassic GyroporeUa, we have 



* Yaucheria plants are often sterile ; and the enlargement of the ends 

 sliould be looked for after the plant has been some time in darkness. 



t By adding a weak (two per cent.) solution of common salt the 

 protoplasm will contract away from the wall owing to the abstraction 

 of water. (" Piasmolysis.") 



X It is not always easy to demonstrate them by such simple staining, 

 and special methods may have to be employed. 



§ The term "' ccenocyte " for such large multinucleate cells is a 

 convenient one, and coming into general use. 



