Jtuie 20, 1889] 



NA rURE 



171 



conception which sticks closest to the facts of organic 

 life. We doubt whether Mr. Alexander's work would 

 have suffered anything by dealing with men and women 

 possessed of moral ideals, instead of ideals floated off in 

 imagination from their bearers ; and we think it would 

 have gained considerably in practical directness, and 

 points of application to the facts of social life. 



We cannot take leave of Mr. Alexander's work without 

 again expressing our warm appreciation of its earnestness, 

 its ability, and its orderly method. It is a valuable con- 

 tribution to ethical literature. C. Ll. M. 



THE ZOOLOGICAL RESULTS OF THE 

 ''CHALLENGER" EXPEDITION. 



Report on the Scientific Results of the Voyage of H.M.S. 

 " Challenger'''' during the Years 1873-76, under the 

 command of Captain George S. Nares, R.N'., F.R.S., 

 and the late Captain Frank T. Thotnson, R.N, Pre- 

 pared under the superintendence of the late Sir C. 

 Wyville Thomson, Knt., F.R.S., &c., Director of the 

 Civilian Staff on board, and now of John Murray, 

 LL.D., Ph.D., &c., one of the Naturalists of the 

 Expedition. Zoology — Vol. XXX. Published by Order 

 of Her Majesty's Government. (London : Printed 

 for Her Majesty's Stationery Office, and sold by Eyre 

 and Spottiswoode, 1889.) 



VOLUME XXX. of the zoological series of the 

 Challenger Reports contains an account of the 

 Asteroidea by W. Percy Sladen, and is without doubt one 

 of the most important of the whole series. 



The Report contains a description not only of the 

 species collected during the cruise of the Challenger, 

 but of those collected during the cruises of the Light- 

 ning, Porcupine, Knight Errant, and Triton. In the 

 Challetiger collection there were 84 genera, 5 subgenera, 

 268 species, and 13 varieties. 184 species and 12 varieties 

 are described as new, and several new genera are 

 established ; the new species and varieties found during 

 the other expeditions bring up the total of new species 

 to 196, and new varieties to 15. 



In the latest summary of the Asteroidea, published by 

 Prof Perrier in 1878, he enumerates 52 genera, which 

 Mr. Sladen reduces to 49, and of these, representatives of 

 no less than 38 were obtained by the Challenger j thus 

 indicating in a striking manner that the collection affords 

 a fair representation of the general character of the 

 Asteroid fauna of the globe. 



The large number of deep-sea forms, belonging to 

 previously unknown types, as well as the very peculiar 

 features distinguishing most of these, demanded a quite 

 new classification ; and Mr. Sladen has framed one in 

 accordance with morphological characters, which is cer- 

 tainly far in advance of any that have hitherto been made. 

 The usefulness of this Report has been greatly increased, 

 without its bulk being materially added to, by a list given 

 under each genus of all its authentic species, and their 

 geographical distribution. 



At the end of the Report there is added a synoptic list 

 of all the known species of recent Asteroidea, with 

 particulars of their geographical distribution, also their 

 distribution in depth and their synonymy. This most 



carefully compiled list will be of the greatest value to 

 all interested in the study of this group. 137 genera 

 and 810 species are therein enumerated. 



The introduction opens with a history of the classi- 

 fication of the Asteroidea, the earliest attempt :it which 

 was made by Linck in 1733. This, which was a purely 

 artificial one, was not improved on by Linna:;us or 

 Lamarck. In 1840, Miiller and Troschel published their 

 well-known classification, chiefly based on the presence 

 or absence of an anal orifice, and on the arrangement of 

 the ambulacral tube-feet ; and this formed the basis 

 of all systematic arrangements of the group until 1875, 

 when Prof. Perrier insisted on the importance of the 

 pedicellariae from a classificatory point of view, in addition 

 to the disposition of the ambulacral feet. A couple of 

 years later Viguier published his elaborate researches on 

 the skeleton of the Asteroidea, and on these also proposed 

 an amended arrangement of the group. In 1854, Prof. 

 Perrier again discussed the question, examining it from 

 Viguier's standpoint, but concluded to retain the pedi- 

 cellariie as the basis of his system of classification, 

 which indeed he but slightly modified. 



Mr. Sladen briefly gives his reasons for dissenting from 

 the views of Perrier ; and passing in review the various 

 morphological features or fundamental points of structure 

 which are common to the whole class, selects the follow- 

 ing : (i) the adaptation of the organism to subserve the 

 functions of respiration and excretion ; (2) the character 

 of the ambulacral skeleton ; (3) the character of the 

 ambital skeleton. 



For the first of these he selects the organs called 

 "papulae" by Stimpson, which penetrate the body-wall 

 in the form of delicate transparent membranous CKca, 

 permitting an exchange of fresh fluid from without by 

 osmosis, thereby introducing oxygen; these "papulae" 

 may be distributed over the whole body, or may be 

 confined to a limited area, and thence the division into 

 the Stenopneusia, and the Adetopneusia. 



The ambulacral skeleton exhibits two modes of growth ; 

 in the one the production of parts is accelerated in 

 relation to the growth of the starfish, in the other the 

 production of parts is retarded, or proceeds pari passu 

 with the general development of the skeleton. The 

 ambital skeleton is formed by the marginal plates and 

 their supplementaries when present ; these the author 

 considers one of the most important systems of plates 

 in the body, as determining form and superficial 

 character. 



The introduction concludes with a summary of the 

 classification as far as the genera, and a synopsis of the 

 orders and families is also given. 



The description of the species calls for no remark, 

 unless the critical one in passing that according to the 

 usual practice the date of the publication of this volume, 

 not the date when the individual sheets contained therein 

 were passed "for press," must be taken as those for the 

 new famihes, genera, and species. No less than 

 109 species and varieties were found at depths 

 from 500 to 2500 fathoms. The volume consists 

 of 935 pages, and is accompanied by an atlas of 118 

 plates, which well merit our special praise. In most 

 instances the figures of the abactinal and actinal aspects 

 of each species is given on one plate, and then in the 



