June 9, J 892] 



NA TURE 



^^l 



say that it is nearly as great as in the whole order of the 

 Scrophularineas. The two principal kinds of variation 

 are the length and the relative diameter of the tubular 

 portion, and the shape of the lips, especially of the upper 

 one, of which there are many curious and even fantastic 

 modifications. Maximowicz's monograph of the whole 

 genus (which is dispersed all round the northern hemi- 

 sphere, and perhaps extends just over the equator in the 

 Andes) includes about 250 species, and a few have been 

 discovered in India and China since. Prain's monograph 

 of the Indian species contains nearly double the number 

 described in the " Flora of British India" in 1884. The 

 systematic part is preceded by an elaborate and masterly 

 essay on the distribution and descent of the species, 

 illustiated by diagrams and a map. The latter might 

 certainly, with a little extra work, have been made 

 clearer. Dr. Prain divides the genus primarily into three 

 groups — namely, Longirostres, Aduticce, and Erostres — 

 based on the modifications of the upper lip of the corolla ; 

 and the names are sufficiently descriptive to indicate their 

 application. Each of these groups contains both op- 

 posite (or verticillate) and alternate leaved species, and 

 is subdivided into a number of sections. So far as we 

 have tried the keys to the sections and species we have 

 found them work admirably, and the descriptions are 

 evidently very carefully written ; but twelve to eighteen 

 lines of description in the ablative absolute without a stop 

 or any variation in type is bewildering, and an innovation 

 that is to be deprecated. Dr. Prain himself appears to 

 have realized this, for in his account of Gomphosteinma 

 his descriptions are shorter and punctuated, with the 

 names of the various organs in italics. 



Dr. King's monographs of the Magnoliaceae and the 

 genus Myristica are written entirely in English, perhaps 

 with advantage, because Latin descriptions are not so 

 easily understood as English by many persons interested 

 in trees. Including the suborder Schizandreae, the num- 

 ber of Indian Magnoliaceas described and figured is 

 forty-five, referred to eight genera. 



Passing on to his monograph of the species of Myristica 

 of British India, we find that he distinguishes sixty-eight, 

 illustrated by sixty-nine plates. By British India, Dr. 

 King understands political British India, including the 

 Nicobar and Andaman Islands, and the territories of 

 the Straits Settlements. Dr. King follows Bentham and 

 Hooker, and others, in referring all the nutmegs to the 

 one genus Myristica, and, as thus limited, it is repre- 

 sented in nearly all tropical countries. Ten years ago, 

 less than a hundred species were described, but Dr. 

 Warburg, who is at present at Kew engaged on a mono- 

 graph of the order, estimates the number now in herbaria 

 at about 200. This great augmentation is almost wholly 

 from discoveries in the Malayan Peninsula and Archi- 

 pelago, New Guinea, and Eastern Polynesia. Dr. King 

 abstains from any attempt to trace the geographical dis- 

 tribution of the species, on the ground that he believes 

 many yet remained to be discovered. But on running 

 through his work we find that. about fifty-four of his 

 sixty-eight species are from the Malayan region, eight 

 from the Deccan and Ceylon, and about six from the 

 Assam and Chittagong region, only two apparently being 

 found as far westward as Sikkim, in North India. Most 

 of the new species are from Perak, a country exceedingly 

 NO. I 1 80, VOL. 46] 



rich in endemic trees. Beyond the distribution indicated, 

 there is one species in North Australia, and four each in 

 Madagascar and Tropical Africa, and perhaps about forty 

 or fifty in America, extending from South Brazil through 

 the West Indies and Venezuela to Central America and 

 South Mexico. The author is careful to explain that he 

 does not regard the present effort as anything approach- 

 ing finality, and anyone acquainted with the genus will 

 understand the difficulties encountered in working from 

 herbarium specimens alone. With one interesting excep- 

 tion {Myristica canarioides, King) the species are dioecious, 

 and female flowers are much rarer than males ; and the 

 fruit, which affords good characters in a fresh condition, 

 is often wanting, or not in a good state for description. 

 But if Dr. King's work is necessarily incomplete, it sup- 

 plies the very best materials for the foundation of a more 

 exact knowledge. The figures, although possessing no 

 great artistic merit, are faithful portraits of authentic 

 specimens of the several species, and, combined with the 

 very full descriptions, are sufficient to enable botanists to 

 determine most of the species. On the other hand, the 

 fine work in the analyses of the flowers is indistinctly re- 

 produced in some of the plates, apparently in consequence 

 of their having been drawn on too small a scale. The 

 flowers, it may be added, of many species, are exceed- 

 ingly small, of some not more than a twentieth of an inch 

 in diameter. But I must draw this notice to a close with 

 the remark that this volume is a monument to the skill 

 and industry of Dr. King and his colleague, and a 

 credit to the native lithographers and printers. One only 

 marvels how the authors, with their multifarious duties, 

 accomplish so much in a tropical climate. 



W. BOTTING HEMSLEY. 



MA THE MA TICAL RECREA TIONS AND 

 PROBLEMS. 



Mathematical Recreations and Problems of Past and 

 Present Times. By W. W. Rouse Ball. (London: 

 Macmillan and Co., 1892.) 



THE idea of writing some such account as that before 

 us must have been present to Mr. Ball's mind 

 when he was collecting the material which he has so 

 skilfully worked up into his " History of Mathematics." 

 We think this because the extent of ground covered by 

 these " Recreations " is commensurate with that of the 

 '• History," and many bits of ore which would not suit the 

 earlier work find a fitting niche in this. Howsoever the 

 case may be, we are sure that non-mathematical, as well 

 as mathematical, readers will derive amusement, and, we 

 venture to think, profit withal, from a perusal of it. The 

 author forewarns possible readers that " the conclusions 

 are of no practical use, and most of the results are not 

 new." This is plain language, but, lest the warning should 

 be too effectual, he adds, " At the same time I think I may 

 assert that many of the questions— particularly those in 

 the latter half of the book— are interesting, not a few are 

 associated with the names of distinguished mathe- 

 maticians, while hitherto several of the memoirs quoted 

 have not been easily accessible to English readers." We 

 have thus stated the author's pros and cons, and remark 

 that he has gone very exhaustively over the ground, and 



