486 



NATURE 



[September 15, 1904 



what tests should be applied to the poles. As the preface 

 to the specification says, a standard specification having now 

 been arrived at as the result of the joint labours of the 

 committee and the makers, it is hoped that, in future, the 

 standards recommended by the committee will be universally 

 adopted by all engineers engaged in designing and installing 

 electrical tramways throughout the British Empire. 



The contents of the June number of the American 

 Naturalist are chiefly bio^rapliiral and botanical. Dr. R. T. 

 Jackson contributing an ai count (with a portrait) of the 

 life and work of the late C. E. Beecher, while Dr. B. M. 

 Davis continues his studies on the plant-cell, and Mr. F. C. 

 Lucas illustrates diagrammatically the range of variation 

 displayed by the blossoms of the common cone-flower (Rud- 

 beclcia hirta). 



The entomological division of the Biological Laboratory 

 of Manila has issued an illustrated Bulletin of fifty-eight 

 pages, by Mr. C. S. Banks, the Government entomologist, 

 on insects affecting the cacao, intended specially for the 

 benefit of cultivators of that valuable crop in the Philippines. 

 Every part of the cacao plant, from the root to the fruit, has 

 its particular enemies, black ants and cicadas attacking the 

 roots, while beetle-grubs bore into the trunii, and various 

 CocCidse and aphides damage the fruit. Fortunately the 

 ravages of certain of these scourges are somewhat checked 

 by other insects which prey upon the species damaging 

 the cacao. Much further work is required before the whole 

 history of cacao-hunting insects can be known, and the best 

 means of checking their ravages devised. 



We have received from the publishers, Messrs. Asher 

 and Co., Bedford Street, W.C., a specimen of a series of 

 fifty coloured biological diagrams, reproduced from the 

 German issue of Messrs. Schroder and Kulls, but with the 

 explanatory legends in English. The plates are 34 by 42 

 inches in size, are printed in from six to eight colours, and 

 are sold at 3s. each. The one with which we have been 

 favoured illustrates the structure and life-history of the cock- 

 chafer, with comparative studies of other beetles. It is 

 admirably adapted for school purposes. Judging from re- 

 duced photographic reproductions of other diagrams, we 

 think those devoted to invertebrates are superior to those 

 illustrative of mammals, so far as drawing is concerned ; 

 but this is a common feature in German zoological art. 



In the September issue of the Quarterly Journal of Micro- 

 scopical Science Prof. E. R. Lankester re-publishes his 

 valuable and profusely illustrated article on the structure 

 and classification of the Arachnida from the tenth edition 

 of the " Encyclopaedia Britannica." One of the points 

 emphasised in this communication is the aflinity of the 

 king-crab (Limulus) and the trilobites to the Arachnida 

 rather than to the Crustacea ; and in summarising the 

 evidence for the arachnid nature of the former, the author 

 alludes to the interesting discovery bv Mr. Pocock of a 

 rudiment of the seventh segment of the scorpion-limb in 

 Limulus, thus bringing the two genera very closely into 

 line. Another interesting feature to which special attention 

 is directed is the mode of evolution of the " lung-book " of 

 the scorpion from the " gill-book " of the king-crab, which 

 appears to be a unique phenomenon. .^mong the other 

 contents of the number in question may be mentioned two 

 papers by Prof. W. B. Benham on new worms from New 

 Zealand, and one by Dr. H. J. Hansen on new parasitic 

 copepod crustaceans. 



P.^RTS iii. and iv. of vol. xlv. of Smithsonian Miscellaneous 

 Contributions contain an important paper by Mr. M. W. 

 NO. 1820, VOL. 70] 



Lyon on the hares, rabbits, and picas, illustrated by a 

 number of figures of their comparative osteology and 

 dentition. Needless to say, the old Linnean genus Lepus 

 is much subdivided, and, unfortunately, the generic and 

 subgeneric divisions adopted by the author by no means 

 coincide with those proposed a few years ago by Dr. Forsyth 

 Major in the Transactions of the Linnean Society — a not- 

 able divergence being the generic separation of the South 

 .African thick-tailed hare from the rabbit. Owing to the 

 complexity of the classification adopted, some of the species 

 of Leporids cannot at present be definitely placed, and are 

 therefore, strictly speaking, without subgeneric names. 

 This will, however, be rernedied in the course of time, and 

 there is no doubt whatever that the present memoir — whether 

 or no its proposed scheme of classification be adopted in its 

 entirety — is an important contribution towards the right 

 understanding of an exceedingly difficult group of mammals. 



A series of Jurassic ammonites from Echizen and 

 Nagato in Japan has been described and figured by Prof. 

 Matajiro Yokoyama (Journ. Coll. Sci. Tokyo, vol. xix:, 

 art. 20). The strata in the province of Echizen comprise 

 a series of shales and sandstones, mostly of fresh-water 

 origin, but divisible into a Lower or Ammonite bed, a 

 Middle or Plant bed, and an Upper or Cyrena bed. The 

 Ammonites include several new species of Perisphinctes, all 

 more or less allied to foreign Lower O.xfordian forms, and 

 one species of Oppelia, which exhibits a distant relationship 

 to Oppelia nobilis of the Tithonian. The strata which have 

 yielded .'\mmonites in Nagato consist of clay-slates, so that 

 the fossils are much compressed. Species of Hildoceras, 

 one of which is near to Am. Levisoni (of Wright) ; of 

 Harpoceras, near to A. lythensis and A. exaratus ; of 

 Coeloceras, near to A. fibulatus ; and of Dactylioceras, near 

 to A. annulatus, indicate that the Nagato slates belong to 

 the Lias, and probably to the upper part of it. 



Some useful hints on the practical development of a farm 

 wood-lot are given in a Bulletin of the Hatch E.xperiment 

 Station of the Massachusetts Agricultural College, issued 

 last May. The products required in this particular case 

 were fire-wood, fencing posts, and lumber for making fruit 

 boxes, besides which some poles and more valuable timber 

 were obtained. The writer, Mr. F. A. Waugh, recommends 

 larch for posts and chestnut and hickory for lumber. The 

 illustrations added are numerous and well chosen. 



The formation of root-hairs in the vascular cryptogams 

 and flowering plants has been studied by Mr. R. G. Leavitt, 

 and his account, which is published in the Proceedings of 

 the Boston Society of Naturalists (April), contains several 

 points of interest. In the case of lycopods, horsetails, and 

 a few ferns, the trichoblasts are determinate, but in all 

 dicotyledons, except the Nymphseaceae and most of the true 

 ferns, root-hairs may arise from any external cell. Of 

 monocotyledons, the Liliiflorae and Spadiciflorse generally 

 conform to the latter type, but in the Helobiefe, Glumiflorse, 

 and Enantioblastje the root-hairs develop from definite cells. 



The annual report of the Botanical Department of 

 Trinidad for the year ending March 31 has been received. 

 The superintendent, Mr. J. H. Hart, states that he has 

 succeeded in raising seedling sugar canes in Trinidad which 

 compare with the best varieties obtained in Barbados, 

 Antigua, and elsewhere. It appears that owing to the 

 practice of cutting the plants annually in May, the seed 

 production and the sucrose content are reduced, so that 

 the experiment will be tried of allowing plants for seed 

 to remain over for a longer period. The [)lantations of 



