Study of Madreporarian Corals. 173 



in coral skeletons, and are as much units of structure, only of 

 a higher order, as are the ultimate calcified cells out of which they 

 are built. The importance of this to the coral worker, inasmuch 

 as it helps to clear the view and correspondingly heightens his 

 confidence in attacking the morphological puzzles that beset him. 

 at every turn, is cei'tainly great. But the new weapon which 

 Miss Ogilvie has given us she proceeds to use herself, and, while 

 heartily acknowledging the debt, I am constrained to say that 

 I cannot agree with the use she makes of it. I write entirely for 

 myself, and Miss Ogilvie may take this comfort to herself, that she 

 has the majority with her, and sins, if it is sinning, in good 

 company. On the other hand, she seems, to me to have carried 

 this tendency to an extreme, which it is to be hoped will in- 

 augurate a wholesome reaction. 



In 1834, Ehrenberg, i-ecognizing the coral stock as the product of 

 a budding process, made the method of budding the factor of prime 

 taxonomic importance, In this he was followed by Dana in 1818, 

 and by Milne-Edwards and Haime. Methods of budding were, 

 however, obviously inapplicable for the classification of solitary 

 corals ; hence characters relating to the structui'e of the calyx had to 

 be sought. The researches of Heider, Von Koch, Fowler, and 

 Bourne have been supplying us with the main differences in the 

 method of building up the coral skeleton. These anatomical studies 

 have now been, as it were, capped by Miss Ogilvie's researches into 

 the minute histology of the skeletal pai'ts. 



Having come to the conclusion that Milne-Edwards and Haime 

 had "practically exhausted the subject from a macroscopic aspect 

 fifty years ago," and further that " habits of the corallum " should 

 not "outweigh considerations of fine structure," Miss Ogilvie 

 started " hoping to find some fairly embi'acive [sic] series of 

 different structural types if such existed in Madreporaria. The 

 result has proved that structural types do exist and form a surer 

 method of determining Madreporarian genera and groups than any 

 other method known to me." As we have seen, the differences 

 of fine structure, on which Miss Ogilvie relies for the classification 

 of the corals, relate to the various groupings of the fascicles with 

 their dark centres and consequently of the trabeculge. 



It is a well-known human failing to treat (perhaps not 

 theoretically, but practically) each new set of differences, especially 

 if they are really important, as if they alone were of any value. 

 There has been a distinct tendency to classify corals according to 

 the anatomy of the calyx, the older, purely macroscopic characters 

 being put very much in the background. And now we have 

 Miss Ogilvie practically pi'oposing to classify corals according to 

 the histology of their skeletons. 



I am, of course, far from objecting to the utilization of skeletal 

 structure or texture in arranging the corals. But hastily to assign 

 to these the first place in face of our ignorance of the inter- 

 dependence of the vital processes themselves, seems to me somewhat 

 unphilosophical. It is quite possible that we shall ultimately find 



