Rei'ieics — WacJmnuth 8f Sjyringer's Monograph on Crinoids. 123 



genus are very striking, and unless they are taken into consideration 

 the describing of species amounts to little more than description of 

 individual specimens. The authors base their observations largely 

 on over a thousand specimens of P. EuntsviUce collected by them, 

 and varying from 9 mm. to 50 mm. in length of crown. So important 

 is work of this nature, that we should have been glad of a far more 

 detailed account and more even than the eight figures which are 

 given of this species. 



Towards the governing problems of evolution and phylogeny, our 

 authors adopt a very cautious attitude, defended in some admirable 

 passages (pp. 166-169). " It is," they consider, " impossible to tell, 

 except perhaps in a very general way, which one of a number of 

 variations marked the line of succession ; or in other words which 

 was for the time being the racial characteristic carrying all others 

 along with it, even though many of them may seem more important." 

 The metaphor is not commendable : at least it seems to me that the 

 racial characteristic is usually some feature that escapes modification 

 just because it is functionally unimportant for the time being ; it 

 follows other changes, itself unchanged. 



The difficulty of deciding which are the important structures is 

 well illustrated by Lyriocrinus. In the two species of this there 

 often occur variations in "characters which have always been 

 regarded as of the utmost significance for distinguishing families and 

 genera," namely, the relation of interradials and basals, and the 

 presence of an anal plate (p. 262). 



Such considerations have led Messrs. Wachsmuth and Springer to 

 shun " the primrose path of dalliance " with evolution, which 

 they fear leads only to " the everlasting bonfire " of genealogical 

 trees. With the modesty that comes of true learning they content 

 themselves " with giving the general facts which [their] investiga- 

 tions seem to pretty well establish, and such interpretation of them 

 as appears reasonably consistent therewith" (p. 166). 



The absurd guesses that one so often sees put forward as sober 

 accounts of phylogeny are enough to compel sympathy with the 

 preceding remarks. But of all virtues prudence is the most 

 uninteresting, and an author should at least have the courage of 

 his convictions. The downfall of so many phylogenetic erections is 

 due to the fact that they are built with their foundations in the air. 

 It is possible, in many cases, to trace the relation of species to 

 species, or the evolution of one genus from another : such statements 

 often attain almost the dignity of facts, and can be checked by 

 stratigraphy and palaeo-geography. Let us begin with these, and, 

 when the relations of genera are fairly settled, let us proceed to 

 those of families. Thus the Orders will take shape before us, and 

 we shall have a truer conception of what their ancestral forms were. 

 Then we can think about the relations of Crinoidea to Cystidea and 

 of Asteroidea to Echinoidea. And some day we may even have 

 a right to speculate on the connection between Echinoderma and 

 Prochordata. 



Now my criticism of this Monograph is that it does not fairly 



