July 29, 1897] 



NA TURE 



291 



leaves, long leaves, short leaves, leaves in two ranks, 

 leaves in spiral arrangement ; the latter being probably 

 the primordial disposition, the two-ranked arrangement 

 being more apparent than real. When the stem and 

 branches grow erect, as they do in some varieties, 

 particularly in that called the Irish yew, the leaves are in 

 spiral order, and when the larva of a little ?iy {Cecidomyia 

 taxi) has its abode in the young buds, the degenerated 

 leaves are in spires. 



In this country, at least, the yew is not generally found 

 in association with other trees of the same or other 

 species. Woods entirely or mainly composed of the tree 

 are rare. One such we know, and it is duly noted in the 

 book before us : we allude to the very remarkable grove at 

 Cherkley Court, near Leatherhead. Here are some ninety 

 to ninety-five acres covered with yew-trees, to the almost, 

 if not complete, exclusion of everything else. They form 

 a most impressive sight, and still more impressive than 

 their numbers is the variety of their forms, their differ- 

 ence " in habit," as gardeners say. They are all growing 

 under like circumstances, and yet there is this astonishing 

 variation in outward form. There is a similar but much 

 less extensive group at Cliveden, the gnarled roots of 

 which, clinging on to the chalk escarpment for dear life, 

 are very picturesque. 



The isolated condition of yew-trees is no doubt due 

 to the trees having been planted where they now are, as 

 in churchyards, or along the roadsides. 



If old yews do not exhibit the highest type of arboreal 

 beauty, there are few trees more imposing. This, no 

 doubt, leads to exaggerated estimates of their age. On 

 this subject quite a literature has grown up. Dr. Lowe 

 has a statistical chapter relating to it in the present 

 volume, reprinted from the Journal of the Linnean 

 Society ; but the results are not uniform, and it is evident 

 that further research on the comparative rate of growth 

 of various trees is to be desired. 



In the book before us the author treats the yew from 

 almost every point of view ; he has been conscientious in 

 his work, accurate in his statements, careful in the verifi- 

 cation of his references — in fact, he has produced a 

 monograph which will be consulted in the future, and 

 which will be read with interest by the lovers of trees at 

 the present day. The book, too, is well printed, well 

 illustrated, and provided with a sufficient index. A few 

 amendments may be suggested— Cliveden is in Bucks, 

 not, as stated, in Berks ; the " De Candolle," so often 

 mentioned, was " Augustin Pyramus," not " Alphonse," as 

 might be inferred ; Gardener's Chronicle should be 

 Gardener^; and the reference "1870- 1890" is very 

 inadequate, seeing that the periodical in question dates 

 from 1 84 1, and contains various references to the yew in 

 its earlier as in its later volumes ; " Helmsley" should be 

 " Hemsley." Reference to Sargent's " Silva of North 

 America," which contains an epitome of almost all that 

 is known concerning the yew, whether in America or 

 elsewhere, would be desirable in a new edition. We 

 suspect from the date of publication that the author of 

 the " Yew-Trees of Great Britain " could hardly have 

 been able to consult the "Silva." The microscopical 

 structure of the wood and leaves should also receive some 

 attention, as it differs considerably from that of other 

 conifers. Yews, for instance, have no resin canals. 

 NO. 1448, VOL. 56] 



OUR BOOK SHELF. 



Untersuchungen uebcr Ban Kernlheilung und Bewegung 

 der Diatomeen. Von R. Lauterborn. Mit i figur im 

 Text u. 10 Tafeln. (Leipzig : Verl. v. Wilhelm Engel- 

 mann, 1896.) 



It is some years since Biitschli declared that centro- 

 somes could be identified during life in certain diatoms, 

 just as Van Beneden had already described them in the 

 segmenting eggs of Ascaris megalocephala. But whilst 

 the worm has furnished the text for numberless papers 

 and memoirs, the diatoms have been passed by and left 

 unheeded. 



Dr. Lauterborn's book will again direct attention to 

 this neglected group, for the observations he records are 

 so startling in themselves, and so unlike anything else 

 with which we are as yet acquainted, that they will 

 urgently require confirmation at the hands of other 

 investigators. 



The author has succeeded in following out many of 

 the details of cell-division in the living cells, and this 

 fact is calculated at once to arrest the attention of 

 cytologists, who are all aware of the great difficulty 

 which exists in makmg much out of a nucleus till it has 

 been fixed and starved. Perhaps the most remarkable 

 statements in the volume are those which are concerned 

 with the origin and structure of the spindle and its rela- 

 tion to the centrosome. The latter structure is a spherical 

 body lying near a depression in the nucleus, but when 

 karyokinesis is about to begin, a second sphere is seen 

 to lie close to the centrosome, and Lauterborn believes 

 it has been actually derived from the latter. 

 This second body is the rudiment of the central 

 spindle, and it wanders about independently of the 

 centrosome, and becomes rapidly of an elaborately 

 complex nature. Ultimately it is found within the 

 nucleus, whilst the centrosome is left outside. Mean- 

 while two masses of protoplasm become apparent in an 

 excentric position at the ends of the barrel-shaped 

 spindle, and these are regarded by the author as repre- 

 senting two fresh centrosomes. Finally the chromo- 

 somes split, become arrayed on the spindle, and are 

 distributed to the two poles. But even in this process 

 we meet with an anomaly, for there seem to be no mantle 

 fibres formed, or indeed any other special mechanism by 

 which the chromosomes find their way to their desti- 

 nation ; they are stated to move automatically to the 

 ends of the spindle. The cell-wall, which divides the 

 diatom into two cells, originates in much the same way 

 as in Spirogyra, beginning at the cell periphery and 

 advancing to the centre. 



The above sketch will show that these plants, of which 

 Surirella has here been taken as a leading type, differ in 

 many respects from other organisms in the mode of their 

 cell-division. But the author by no means confines him- 

 self to the topic of karyokinesis. The structure of the 

 protoplasm, and of its varied organised inclusions, as well 

 as the remarkable movements exhibited by the plants 

 themselves, all come in for a share of attention. In 

 short, the book is one which should serve to stir up 

 research into a group of plants which have hitherto been 

 too much regarded as the special property of amateurs 

 who, with the aid of expensive microscopes, delighted to 

 count strite and to make species. 



Journal and Proceedings of the Royal Society of New 

 South Wales for 1896. Vol. xxx. Edited by the 

 Honorary Secretaries. Pp. xxiv -f 410 -f cxlviii. 

 (London Agents : George Robertson and Co., 1897.) 



The twenty-four papers in this volume testify to scientific 

 activity at the antipodes. In his presidential address 

 Prof. T. W. Edgeworth David sums up the contributions 

 of New South Wales to scientific knowledge during 



