October 22, 1891] 



NATURE 



;89 



of the Garden and School. The present volume, there- 

 fore, really begins the series of annual reports, and to- 

 gether with the reports we have a revision of the North 

 American species of Epilobium. In the earlier part of 

 the book details are given of the appointment of six 

 garden pupils to scholarships in accordance with a reso- 

 lution adopted by the trustees at a meeting held in 

 November 1889. Each scholarship conferred may be 

 held by the recipient for a period not exceeding six years, 

 subject to certain conditions. The holders of scholar- 

 ships are repaid for their services to the Garden, and at 

 the expiration of the six years are entitled to examina- 

 tion by the Garden Committee. Cn passing such exa- 

 mination to the satisfaction of the Committee and Director, 

 they receive a certificate of proficiency in the theory and 

 practice of gardening. The only scientific paper in the 

 volume is, as we have just mentioned, a revision of the 

 gtnvLS Epilobium, iht American species occurring noith 

 of Mexico being those studied. This genus differs from 

 all the other capsule-bearing Onagracece, except the Cali- 

 fornian Zauschneria, in having its seeds provided with 

 an ample coma at the apex. While it reaches great 

 development in New Zealand, Epilobium is essentially a 

 genus of temperate and cold climates, and the most 

 widely distributed species are those of Arctic and 

 Alpine regions. In Alaska a few such species [occur, 

 which are otherwise confined to the adjacent part 

 of Asia. More widely distributed Arctic-Alpine immi- 

 grants from the Old World to the New are E. spicatujn, 

 E. latifolium, E. palustre, E. alpinu?n, &c. E. hirsutum, 

 E. parviflorum, and E. adnatuvi, also occur as acci- 

 dental waifs. The genus passes into South America 

 along the backbone of the continent ; few members of 

 this family extend very far across the Mexican boundary 

 in either direction. The most interesting biological 

 features of the genus are those connected with the means 

 of vegetative propagation, pollination, and dissemination. 

 The contrivances by which species survive the winter 

 and are vegetatively propagated, in this respect attain an 

 extreme degree of differentiation, one in particular having 

 acquired aerial bulblets. The large-flowered species 

 appear to be regularly proterandrous, the duration of the 

 dichogamy being brief in most of them, and the smaller- 

 flowered seem to be always synacmic and self-fertile, 

 although with the probability of frequent intercrossing by 

 aid of insects attracted by the nectar which is secreted 

 within the calyx tube. The genus is of no striking 

 economic value. The North American Epilobia have 

 been mostly described by De CandoUe, Torrey and Gray, 

 Haussknecht and Barbey ; the more notable works of 

 more limited range being Hooker's " Flora Boreali- 

 Americana," and Brewer, Watson, and Gray's " Botany 

 of California." Prof. Trelease in his revision enumerates 

 38 species, which number includes the following novel- 

 ties : E. holosericeum, E. delicatulutn, and E. clavatum. 

 The well-known sections Chamcenerion and Lysimachion 

 are still adhered to, the latter, of course, being by far the 

 larger. In the analytical key the main divisions depend 

 on whether the stigma is deeply 4-lobed or 4 cleft, or 

 entire or only notched. Subdivisions are founded on 

 whether the seeds are smooth, or papillately roughened- 

 The name E. spicatum, Lam., is used instead of angusti- 

 folium, the typical angustifolium of Linnaeus being, 

 NO. T 147, VOL. 4 



according to Prof Haussknecht, what is commonly known 

 as E. Dodonai, Vill. We are glad to see that Prof. Tre- 

 lease differs from Prof. Haussknecht in not adopting a 

 new name for what is left of the original E. alpinum 

 The E. alpinum of Linnaeus included with this E. 

 Hortionanni and E. anagallidifolium, but we think that 

 the name may well stand for one of the segregates. The 

 genus Epilobium has always proved a difficult subject ; 

 and Prof. Trelease is to be congratulated on his careful 

 treatment, and successful arrangement, of the North 

 American members. The 48 plates will be found of 

 great help to students of these plants ; they are not quite 

 of uniform merit, but, taken as a whole, they give the 

 essential details, stress being laid on the varied form of 

 the stigma and seed. Additional illustrations are some 

 well-reproduced photographs taken in the Garden, and a 

 plan of the grounds (scale yig) in five sections. 



E. G. B. 



OUR BOOK SHELF. 



The Story of the Heavens. By Sir Robert Stawell 

 Ball. Eighteenth Thousand. (London : Cassell and 

 Company, 1891.) 



In the preface to this edition, Sir Robert Ball remarks 

 that he has taken the opportunity to " revise the work in 

 accordance with the progress of astronomy during the 

 last four years," and, generally speaking, new facts and 

 theories are briefly referred to. A few points, however, 

 are hardly brought up to date. For example, the spec- 

 trum of the Andromeda nebula is said to be " a faint 

 continuous band of light" (p. 462), although it is 

 now definitely known that this continuity does not exist. 

 We also find no reference to the many stars now 

 known to have bright lines in their spectra. The author 

 thus misses a chance of exercising his well-known descrip- 

 tive ability in an account of the connection between such 

 stars and nebulae ; the similarity of the two being so 

 considerable that Pickering has followed Lockyer in 

 arranging them in a single group. Dr. Huggins's old 

 view as to the coincidence of the nebula line with 

 nitrogen is mentioned merely to be dismissed as erro- 

 neous. Why, therefore, is no notice taken of the 

 suggested magnesium origin of the line — for, on any pub- 

 lished evidence, the edge of the magnesium fluting is 

 nearer the proper position than the nitrogen double? 

 We would also point out that, according to recent obser- 

 vations, the apex of the sun's way is much nearer Lyra 

 than Hercules. Telescopic changes in comets are fully 

 described, but the accompanying changes in their spectra 

 are not touched upon. Motions of stars in the line of 

 sight are considered ; but not those of nebula;, although 

 Mr. Keeler's observations have been published for some 

 time. In fact, it may be said that there is a tendency 

 to eschew spectroscopic questions, and hence much of 

 the most beautiful part of the story of the heavens is left 

 untold. 



Notes on Elementary Physiography. By Horace C. 

 Martin. (London and Manchester : John Heywood, 

 1891.) 



The author has collected a lot of scraps of information 

 from standard writers on physiographical matters, and 

 has strung his gleanings together to form this book. And 

 if he were an adept at compilation, and knew how to best 

 arrange and connect facts, this plan of printing extracts 

 verbatim might be commended. But when Mr. Martin 

 selects notes which by themselves are incorrect, and inter- 



