OCTOBEB 30, 1908] 



SCIENCE 



609 



of a Nilghai can see at once how the spike- 

 like horns spring straight upward, bending 

 slightly forward, and how the near horn hides 

 its fellow. 



The knowledge of this animal would un- 

 doubtedly have reached the ancient Persian 

 civilization from the trans-Indus region, and 

 the artists of the period would very naturally 

 have graven but a single horn in bas-relief 

 profile. Further evidence that this animal 

 was known to the ancient Persians is to be 

 found in the name itself — " Nilghai," or 

 " Nylghau," being of Persian origin and 

 meaning " blue bull." The species first be- 

 came known to the modern world of Western 

 Europe about 1745, and was described and 

 figured in Philosophical Transactions for that 

 year by Dr. Parsons, in a paper entitled " An 

 Account of a Quadruped brought from 

 Bengal, and now to be seen in London." In 

 Philosophical Transactions for 1770 Dr. Will- 

 iam Hunter published a very full account of 

 this animal from living specimens brought to 

 England, and bestowed upon it the native 

 name " Nylghau." 



As the unicorn of Ctesias failed to 

 materialize in the fauna of any country, it 

 was relegated to the land of fabulous crea- 

 tures, and became conventionalized in the art 

 of the ancient and medieval world. If, as Mr. 

 Eastman points out, its origin is to be found 

 in the bas-reliefs on the walls of Persepolis, 

 then, undoubtedly, it must have been a figure 

 from some living prototype, and this proto- 

 type could, it seems to me, be none other than 

 the Nilghai, the only Asiatic ruminant with 

 horns so placed as to give rise to such a con- 

 ception. 



Spencer Trotter 



swaethmore colueqe 



SCIENTIFIC BOOKS 

 A Manual of the North American Gymno- 

 sperms, exclusive of the Cycadales, but to- 

 gether with certain exotic species. By 

 David Pearce Penhallow, D.Sc, Mac- 

 Donald Professor of Botany, McGill Uni- 

 versity, 8vo, pp. viii + 374, with 48 text 

 illustrations and 55 plates. Boston, Ginn & 

 Company, The Athenaeum Press. 1907. 



The book is prepared for " working 

 botanists," " engineers, and especially forest- 

 ers." Por the latter the author hopes that his 

 histological diagnoses may be of great value 

 in the difficult task of identifying the various 

 species of coniferous woods in the absence of 

 the usual botanical data. The author tells us 

 that 



The present work had its origin in 1880 in an 

 attempt to construct a system of classification for 

 the North American Coniferae based upon the 

 anatomy of the vascular cylinder of the mature 

 stem. The fundamental idea was that such a 

 classification would prove of great value in the 

 identification of material used for structural pur- 

 poses, but investigations had not been carried 

 very far when it became manifest that some such 

 arrangement was imperatively demanded in other 

 directions and for purposes of a more strictly 

 scientific character. 



The author here refers to the value of such 

 data in the study of fossil plants. 



The book is divided into two parts, the 

 first, devoted to the general anatomy of the 

 conifers, covering half of the volume. In this 

 the reader or student finds very useful general 

 directions for the preparation of material, dis- 

 cussions of growth-rings, tracheids, bordered 

 pits, medullary rays, wood parenchyma, resin 

 passages, etc. In part second the author 

 arranges and describes the genera and species 

 of North American Gymnosperms (exclusive 

 of Cycadales) under three orders, viz., Cor- 

 daitales (including the extinct Gordaites, and 

 the surviving Dammara, and Araucaria), 

 Gingkoales (including the surviving GingTco) 

 and Coniferales (including seventeen genera 

 of surviving or recent gymnosperms). Here 

 we have the species of each genus separated 

 by means of a convenient key. Then we have 

 the species arranged systematically, and in 

 each case the scientific name is first given, 

 with a citation of the authority. Next fol- 

 lows a paragraph descriptive of the transverse 

 section, a second for the radial section, a third 

 for the tangential section. For extinct species 

 the mode of fossilization and the geological 

 position are given, while for living species 

 data are given as to specific gravity, fuel 

 value, strength, etc., and geographical distri- 

 bution. 



