INTKODUCTION. CXXl 



Of the Cheilostomata be says : — " Hoc eniin certum 

 dicimus, ut ex origine simili progresses sint hce forma, 

 quarum colonia et individua in uno vel altera studio 

 evolutionem sistere possint ; " and he summarizes his 

 doctrine thus : — " Si sermone theoretico uti licet, sicut 

 individua, sic etiam species et ceterce divisiones, qu(B 

 systema naturale conficiunt, leyibas evolutionis suhject<e 

 sunt." 



Certainly a most interesting field of inquiry is hei-e 

 opened before us ; and though we may not be prepared at 

 present to accept Prof. Smitt's view (and as little are we 

 prepared to reject it), there can be no doubt that it should 

 give for some time the direction to investigation. 



It seems to me, however, that the attempt at a genea- 

 logical arrangement in detail, if it should ever be feasible, 

 is certainly premature, and that even in the hands of so 

 able and conscientious an observer as Prof. Smitt it 

 yields any thing but a satisfactory result. He himself 

 admits the serious ditiiculties attendant upon the work, 

 some of which are never likely to disappear *. 



It must, I think, be admitted that his reduction of the 

 older species is, to a considerable extent, excessive, whilst, 

 at the same time, the grounds on which forms are asso- 

 ciated in one and the same specific group are often 

 questionable, and no small amoaiit of confusion is 

 caused by the blending of species of doubtful affinity 

 ujoder a single name. 



Our knowledge of the morphology of the class will be 

 lietter promoted at the present stage by keeping separate. 



* " Iterum et itei'um memoranda c^t ignorantia nostra pracipiie spe- 

 c'ierum extiuctai-um, qua; liinite.s harum divisionum incorlos facit."' — ffi/'y. 

 1867, p. 486. 



