SOME NEW BOOKS. 



The Text-book Writer among the Echinoderms. 



Lehrbuch der Vergleichenden Anatomie . . . Vierte Abtheilung. 

 Vergleichende Anatomie der Echinodermen und Enteropneusten. By Dr. 

 Arnold Lang. 8vo. Pp. xvi., 871-1198, 251 text figures. Jena: G. Fischer, 

 1894. Price, 7 marks. 



As a condensed account of the morphology of the Echinoderma, this 

 should prove a useful compilation, and one cannot but admire the 

 assiduity of the compiler. But it is a compilation and little more. 

 One has not to read many paragraphs before becoming aware that the 

 writer is no specialist in this subject. From one point of view, this 

 may be thought an advantage ; from another it is certainly a dis- 

 advantage. The author of a text-book such as this should combine 

 the learning of the specialist with the wide outlook and broad grasp 

 of the philosophical biologist. The demand, however, is, at least at 

 the present day, an impossible one. It can never be stated too often 

 or too strongly that the single author text-book, on any such extended 

 scale, is foredoomed to failure. The specialist in each branch knows 

 •how many years it takes him to grasp the rudiments of his subject, 

 and he simply laughs at the idea of any man, even so clever a man as 

 this eminent Swiss investigator and professor, venturing to collect 

 and retail the knowledge of all the groups of the Invertebrata which 

 has been and is being laboriously acquired by a multitude of scattered 

 workers. 



It seems, however, inevitable that such a book as this, devoting 

 as it does 284 pages to a single group of animals, the Echinoderma, 

 should be criticised from the standpoint of the specialist. It is all 

 very well for the student to say that he understands a certain book, 

 and reads it with pleasure, or for the philosopher to admire the 

 masterly handling of facts and theories ; but what if your expert 

 comes along the next minute and says — as he alone has a right to 

 do — that the language is incorrect, the very facts wrong, and the 

 theories those of the day before yesterday ? I propose, therefore, to 

 deal with this book from such vantage ground as I may have gained 

 by several years study of some of the animals dealt with in its pages ; 

 and, though such a proceeding may seem rather unfair to the author, 

 it is surely fairer to the public, and, in the long run, of more use to 

 the author. It may also advantage specialists themselves. For, if 

 specialists write in such a way that an acute observer and able writer 

 cannot render their views correctly, then it is just possible that some 

 of the fault may lie with the specialists and not with the compiler. 



The class to which I propose chiefly to direct attention is that of 

 the Crinoidea. These, it must be admitted, are remarkably difficult 

 animals to study, and the difficulty is enhanced by the fact that so 

 many, and those the more important, are found only in the fossil 

 state. One can but sympathise with the poor man who undertakes, 



