PORITES. 9 



come across sentences expressive of the difficulty of always being able to decide as to which of 

 the two any specimen should belong, but we are surprised that these great phantom species 

 should have still been holding their own and imposing so completely upon the human mind. 

 And yet, on the other hand, can it be wondered at ? Surely not, when we remember how 

 one naturalist after another has been hopelessly bewildered by the caKcles of this genus. 

 To this supreme difficulty the confusion must largely be attributed. There was 

 nothing apparently to lay hold of in these imaginary species — nothing but the names, which 

 referred solely to growth-form. Little or nothing was known about the value of tlie gi-owth- 

 form. While on the one hand, to ignore the calicles was impossible, on the other hand, to 

 study them was only to be altogether bewildered, and disheartened with the whole subject. It 

 could only have been some such bewilderment which prevented the next writer, Dr. Eathbun, 

 from realising liow valuable was his chief observation. 



The next, and in some respects the most important work on the Porites of these American 

 waters is Dr. Eathbun's Catalogue of the Specimens in the U.S. National Museum.* It is 

 important (1) because it gives drawings of eleven different forms of Porites with their localities ; 

 (2) because it records an oljservation which will help more than all our reasoning could do to 

 break down an old-established custom, and put the whole method of coral taxonomies upon 

 a scientific basis. For to Dr. Eathbun must belong the credit of first indicating the unit of 

 classification of the future. Dr. Eathbun himself, however, endeavoured to continue in the 

 beaten path ; he allowed himself to be imposed upon by the supposed Lamarckian species. 

 Only in the case of one encrusting form from Brazil did he rebel and declare that it was not 

 P. astrccoides (see p. 29) ; but all the many different branching forms (and how many, and 

 how different, see for example his own figures) had to be ruthlessly forced into either clavaria 

 or furcata. The difficulties experienced in having to decide into which of the two species some 

 of the forms should go, forced from him the typical complaint of system atists who have to 

 distribute their specimens among imaginary species. He regretted that so little knowledge 

 about the specimens was available ; fuller and better notes should be made by the collectors, 

 notes which might possibly " serve to show relationship " in what is otherwise the blindest 

 guesswork. The paragraph recording these all too familiar difficulties ends with the following : 

 " Fortunately, in the last and largest collection received from Florida, all the specimens from 

 each locality have been kept together, and it is shown that each spot has its peculiar variety or 

 varieties, differing more or less from all the others." 



This priceless observation — which, let me add in passing, confirms at a stroke the conclu- 

 sions to which the laborious work of writing these volumes had been slowly driving me — should, 

 one would have thought, have instantly marked out the line of the work, for these " varieties " 

 were clearly the units for the research. But, no ' the imaginary species had not yet lost their 

 hypnotic power. One more step had still to be taken before a real path was to be discovered. 



This last step logically necessitated by Dr. Eathbun's work, was first perceived and 

 eventually taken by Dr. Gregory.f It was clear, as above pointed out, that it was quite 



* Proc. U.S. Nat. Mus. x. (1S87) jj. 354. f Quart. Journ. Geol. Soc. h. (1895) p. 255. 



c 



