i6S 



NA TURE 



\_fiine 19, 1 ! 



the female flower of a Carex is represented by " a single 

 ovary inclosed in a loose bag, which may perhaps be the 

 final rudiment of a tubular bell-shaped corolla like that of 

 a hyacinth" ! Surely the nature of the utricle of a Carex 

 has been clearly enough demonstrated by the structure 

 of the flowers of monstrous specimens and of allied 

 genera. To complete his remarks upon the sedges he 

 adds a footnote, in which he says : " The sedges are not 

 in all probability a real natural family, but are a group of 

 heterogeneous degraded lilies, containing almost all those 

 kinds in which the reduced florets are covered by a single 

 conspicuous glume-like bract." Now there is probably 

 hardly any large order in the vegetable kingdom so 

 natural as that of the Cyperacete, so little connected with 

 any other, and of which the genera are so closely allied 

 together, as is proved by the comparatively small number 

 of genera in it, and the large number of species which 

 many of the genera contain. 



The wheat plant being a degraded lily, it becomes 

 necessary to trace the development of the flower of the 

 one into that of the other, which is done by considering 

 the palea of the wheat-flower as homologous with the 

 calyx, and the lodicules as representing the corolla, a 

 view which has long been considered untenable. 



The two essays upon the distribution of plants call 

 for s< ime comment. Here the author is on firmer ground, for, 

 thanks to the researches of Forbes and Watson, we have a 

 much clearer notion of the origin of our flora than we can 

 have of the pedigrees of the plants themselves. At the same 

 time we must take exception to the suggestion that the seeds 

 of the northern Holy Grass, which Robert Dick discovered 

 in Caithness, were introduced into New Zealand from 

 Siberia upon the feet of a belated bird. The plant in 

 question does not occur, as far as is known, in New 

 Zealand. The species which does occur both in New 

 Zealand and Europe is found throughout the temperate 

 Antarctic zone, extending even to the Cape. Nor is this 

 distribution, as the author states, a very rare and almost 

 unparalleled coincidence. The fact is that there is a very 

 considerable number of plants common to the north 

 and south temperate regions, most of which occur in 

 North America, and seem to have descended towards the 

 Antarctic regions along the line of the Andes. 



But, apart from improbabilities in theory, there are 

 numerous statements which cannot fail to convey erro- 

 neous impressions of plant-physiology. What, for in- 

 stance, could be more misleading than the following 

 statement concerning Potentillas ? Those "which raised 

 their leaves highest would best survive, while those which 

 trailed or kept closely along the ground would soon be 

 starved out for want 0/ carbonic acid.'" It is not the 

 absence of carbonic acid gas that the plant would suffer 

 from, but from the loss of light by which it could utilise it. 

 These statements, and many others of a similar nature, 

 suggest that Mr. Grant Allen has confined his observa- 

 tions too much to the flora of the British Islands. It is 

 utterly impossible to form any correct idea of the history 

 of the evolution of a plant without knowing thoroughly 

 the structure of all the plants in any way related to it, 

 and without having, moreover, a much clearer knowledge 

 of the effects produced by external circumstances in modi- 

 fying organs than we at present possess. In the mean- 

 time dogmatic statements concerning the evolution of 



any given plant are in the highest degree unsatisfactory, 

 and likely to lead to error. 



The book is nicely got up, and the language is in that 

 easy and fluent style in which Mr. Allen is so proficient, 

 and which goes so far towards investing the driest details 

 of science with a poetical and even romantic interest. 



H. N. R. 



OUR BOOK SHELF 



Wonders of Plant-Life. By Sophie Bledsoe Herrick. 



(London: W. H. Allen and Co., 1884.) 

 This is another well-intentioned but unsuccessful attempt 

 to deal in a popular style with some of the more sensational 

 parts of the science of botany. Inaccuracy is again the 

 glaring fault : thus we read on p. 4 that " vegetable cells, 

 in the earlier stages of development, generally approxi- 

 mate to the sphere in form"; on p. 17 that the vessels 

 " serve to convey air through the tissues of the plant," 

 and " are the lungs of the plant " ; and again, on p. 24, 

 that the red and ultra-red rays are those actively con- 

 cerned in the process of assimilation. Similar inaccu- 

 racy may be traced in those of the illustrations which 

 are original ; for example, the drawing of Penicillium on 

 p. 60. The frequent production of popular treatises shows 

 that there must be some demand for such books. It is 

 much to be desired that some botanist who is really 

 master of his subject would take the matter up, and write 

 in a popular style a trustworthy account of those parts of 

 the science of botany which are of especial interest to the 

 general public. 



Histological Notes for the Use of Medical Students. By 

 W. Horscraft Waters, M.A. (London : Smith, Elder, 

 and Co., 1884.) 

 In the introduction to this little work of 65 pages Mr. 

 Waters states that, in taking the class of Practical His- 

 tology at the Owens College Medical School during the 

 summer sessions of 1882-83, it had been his custom to 

 give each student " sheets " containing a short account ot 

 the chief points to be observed in the specimens for ex- 

 amination. The present work has grown out of these 

 notes, after careful revision and additions thereto by the 

 author. Students of histology have already numerous 

 similar treatises placed at their disposition, describing 

 the various methods of staining, clearing, and mounting 

 specimens ; but room will always be found for additional 

 ones bearing on this subject, provided they are the out- 

 come of practical experience. These notes have been 

 carefully prepared ; the directions given are clear and 

 concise, and beginners cannot do better than carefully 

 follow them. 



LETTERS TO THE EDITOR 

 \The Editor does not hold himself responsible for opinions extressed 

 by his correspondents. Neither can he undertake to ret urn, 

 or to correspond with the zoriters of, rejected manuscripts. 

 No notice is taken of anonymous communications. 

 [ 77. .' Editor urgently requests correspondents to keep their letters 

 as short as possible. The pressure on his space is so great 

 that it is impossible otherwise to insure the appearance even 

 of comtnunications containing interesting and novel facts.'] 



Pile-Dwellings on Hill-tops 



I ohserve this question to the fore in Nature of February 21 

 (p. 382), and as I have lived many years among races who build 

 various forms of pile-houses, and have often resided in them for 

 a time, I trust you can allow me a few words on the subject. 

 The custom seems attributed to several causes, i.e. to excessive 

 moisture and as a protection against wild beasts, by Mr. Keane ; 

 to excessive rain and a wet climate, by Col. Godwin- Austen ; to 

 damp exhalations from tropical soil, by Mr. Dallas ; and to the 



