REPORT ON CORALS— EXPLANATION OF PLATES. 209 



EXPLANATION OF THE PLATES. 



HYDROCORALLIN.E— I. to XIV. 



Note. — The greater part of the figures relating to the soft structures of the Hydro- 

 corallinae have been prepared so as to represent by means of ideal sections the con- 

 clusions as to structure arrived at by prolonged study of long series of preparations. 

 It would have been impossible to give facsimile drawings of all the preparations from 

 the study of which facts of importance were arrived at, and thus to lay the evidence 

 before the reader in a pictorial form. The practice of illustrating scientific papers 

 treating of minute anatomy by figures which profess to be facsimiles of preparations, 

 and in which often all defects due to breakage of sections or obliquity of the line of 

 cutting are reproduced, seems to me much to be deplored, and only tends to create 

 confusion and needlessly increase the number of figures without in any way enhancing 

 the credit which will be given to the results. The drawings can never be so accurate 

 as to stand in the place of preparations ; they will always represent to some extent 

 the author's views as to what is to be observed in the preparations. It seems far 

 better that in the modern stage of the science of finer anatomy, drawings should represent 

 the results attained, in as complete and concise a form as can be devised, so as to 

 convey these results to others almost at a glance, if possible. 



In the present figures all the histological details, as well as the major features of 

 the structures represented, have been drawn accurately to scale by means of a series 

 of micrometric measurements. The amount of magnification in diameters is given at 

 the bottom of each plate or figure. Since in the majority of the plates ideal sections 

 through complex canal meshworks are represented, the canals composing the mesh- 

 works are necessarily shown as cut open in all directions. 



PLATE I. 



Drawings of the ccenostea of the several species of Stylasteridae of which the cor- 

 responding soft tissues are described. 



Fig. 1. Sporadopora dichotoma. Young vigorous specimen which was obtained in 

 the living; condition. Natural size. 



O 



(zooi. CHALL. EXP. — rART VII. — 1880.) G 27 



