January 12, 1893] 



NATURE 



243 



recent British engines. An illustration is given of an 

 engine of this type, as well as a full-page engraving of 

 a compound locomotive with a similar boiler. This 

 compound is very different from the Webb or Worsdell 

 engines common in this country, being the design of the 

 superintendent of the Baldwin Locomotive Works. The 

 cylinders are outside the frames — there are two on each 

 side, viz. one high-pressure and one low-pressure. The 

 distribution of the steam being effected in each pair by 

 one piston valve, each pair of pistons is connected to 

 one crosshead, coupled in the usual way to the wheels. 



A compound engine of the " Webb " type is also illus- 

 trated. This engine was constructed to Mr. Webb's 

 designs in this country for the Pennsylvania Railway in 

 1889. It is stated that the results of experiments showed 

 a saving of fuel over the ordinary engine of from 20 to 

 25 per cent. 



This book is so full of interesting matter of so varied 

 a nature that it would be possible to prolong this notice 

 far beyond the space available. Take, for instance, 

 agricultural machinery ; the Price ploughing outfit is 

 typical of the rest, consisting of a traction engine drawing 

 four gangs of three ploughs, the twelve ploughs cutting 

 eleven feet wide. The subject of milling tools is also of 

 interest, because it is only during the last few years 

 British engineers have used this means of shaping 

 metals, the system having been brought into general use 

 in the States. 



Under the head of the manufacture of steel all the 

 usual processes are described. We are informed that the 

 Whitworth compression process is only partly successful 

 in the formation of sound ingots ; with this statement we 

 cannot agree ; the Whitworth steel ingot after com- 

 pression is certainly sound throughout. 



Taking into consideration the great mass of informa- 

 tion contained in the 900 odd pages of this work, and the 

 general excellence of the matter accumulated, it is only 

 just to congratulate the editor on the completion of a 

 work which must prove useful to many, and which should 

 find a place in all technical libraries. The volume goes 

 far to describe modern American mechanism, exhibiting 

 the latest progress in machines, motors, and the trans- 

 mission of power. 



SEEDLINGS. 

 A Contribution to our Knowledge of Seedlings. By the 

 Right Hon. Sir John Lubbock, Bart., M.P., F.R.S., 

 D.C.L., LL.D., with 684 figures in text. In two 

 volumes. (London : Kegan Paul, Trench, Triibner 

 and Co., Ltd., 1892.) 



SEEDS and seedlings have occupied the attention of 

 Sir John Lubbock for a somewhat lengthened 

 period. They have formed the subject of various com- 

 munications, on his part, to the Journal of the Linnean 

 Society and other publications. In the present volumes, 

 modestly styled a "contribution," he gives us the details 

 upon which his inferences have been founded. 



The physical and chemical aspects of germination are 

 entirely passed over, but the morphological phenomena 

 are treated with a fulness never before attempted. The 

 author has availed himself of the resources put at his dis- 

 posal by the authorities at Kew, where the larger propor- 

 NO. 121 I, VOL. 47] 



tion of the seedlings described were grown expressly for the 

 purpose. The Natural History Museum and the Cam- 

 bridge Botanic Gardens have also been requisitioned, and 

 much help has been rendered by capable assistants, whilst 

 the services of Sir Joseph Hooker and Mr. Rendle, in look- 

 ing over the proof sheets, are duly acknowledged. A work 

 of such dimensions, crowded with detail, could hardly have 

 been produced without such zealous co-operation. Never- 

 theless unity of plan and uniformity of treatment are 

 conspicuous throughout, and thus comparison is readily 

 effected. 



Some previously published papers in the Journal of the 

 Linnean Society, dealing with the causes which deter- 

 mine the form of leaves and cotyledons, are reprinted 

 as the introduction to the treatise. The conclusion 

 therein arrived at is that the form of the embryo, and 

 especially that of the cotyledons, is essentially influenced 

 by the form of the seed. On p. 78 the author begins 

 the detailed examination of seedlings taken from almost 

 all the orders of flowering plants. Five hundred and 

 thirty succeeding pages in the first volume, and five 

 hundred and eighty-eight in the second volume, are thus 

 occupied. This little bit of statistics will serve to show 

 the amount of detail which is contained within these 

 volumes. The plan adopted is to give, first of all, a 

 general sketch of the principal modifications exhibited 

 by the fruit and seed in each order. Then follows a 

 more detailed description of the seed and of the seedling 

 plant in various representatives of the order. As these 

 descriptions are identical in plan throughout, they are of 

 great value to the student of comparative morphology. 

 Naturally some orders are much better represented 

 than others, but sometimes the omissions are rather 

 unfortunate. In the genus Araucaria, for instance, 

 seedling representatives of which are common in botanic 

 gardens and nurseries, the diversities in the form of the 

 seedling and in the mode of germination are very remark- 

 able. " Characters " derived from the seedling plant 

 have been recognized as of the highest importance for 

 classificatory purposes since the time of John Ray 

 (1682-1703).^ 



But whilst this is generally the case, such extraordinary 

 exceptions as that mentioned in Araucaria are very 

 noteworthy, and not less so because the genus in ques- 

 tion is one of the very oldest of which fossil botanists 

 have cognizance. 



Myrtaceae and Sapindacea^ are remarkable for the ex- 

 tremely diverse character of the embryo in different genera, 

 and of which due note is taken in Sir John Lubbock's 

 book. In Rosaceae, on the other hand, the diversity is 

 much less, nor is there" any important morphological 

 difference in the seedlings of the great order Compositae, 

 and scarcelymore in Umbellifer9e,sofaras they are known. 

 These are facts of great significance with reference to the 

 theories of inheritance and relative antiquity of groups. 



I It may not be without interest to cite what Ray "says on this matter :— 

 " Flonferas dividemus in dicotyUdones quarum semina sata binis foliis 

 anomalis. seminahbus dictis, quae cotyirdonum usuii prae tant, e terra 

 exeunt vel in bin is saltern lobos dividunnir, quamvis co^ supra terram foli- 

 orum specie non crferant ; et monocotyUdoni'S qua: nee folia seminalia bina 

 efferuni nee lobos binoscondu.it." I'hus Ray noi only rec gnirrd the pre- 

 sence of oneorof tw ■ cotyled ins, hut als ■ their nature and ihe.r epi- or 

 hyp geai condiiion. As Ray has been ment'oned, it is cer amiy not inap- 

 pr priaie to allude to Grew alsi., for the tirst chapter of his "Anatomy of 

 PI. nts " (i68j). and tue whole of the fourth book is devoted to the seeds 

 and seedlings and in perusing them the reader will perceive that Sir John 

 Lubbock has in a few cases been anticipated by his celebrated predecessor. 



