PALAEONTOLOGY AND PHYLOGENY. 587 



mals with which we are acquainted have come into exist- 

 ence. They will remain true, so far as they are true at all, 

 even if it should be proved that every animal species has 

 come into existence by itself and without reference to any 

 other. On the other hand, if there are independent grounds 

 for a belief in evolution, the facts of morphology not only 

 present no difficulty in the way of the hypothesis of the evo- 

 lution of the Invertebrata from a common origin, but readily 

 adapt themselves to it. 



Hence the numerous phylogenic hypotheses which have 

 of late come into existence, and of which it may be said that 

 all are valuable, so far as they suggest new lines of investi- 

 gation, and that few have any other significance. I do not 

 desire to add to the number of these hypotheses ; and I will 

 only venture to remark that, in the absence of any adequate 

 palaeontological history of the Invertebrata, any attempt to 

 construct their Phylogeny must be mere speculation. 



But the oldest portion of the geological record does not 

 furnish a single example of a fossil which we have any rea- 

 sonable grounds for supposing to be the representative of the 

 earliest form of any one of the series of invertebrated ani- 

 mals ; nor any means of checking our imaginations of what 

 may have been, by evidence of what has been, the early his- 

 tory of invertebrate life on the globe. 



Already indications are not wanting that the vast multi- 

 tude of fossil Arthropods, Mollusks, Echinoderms, and Zoo- 

 phytes, now known, will yield satisfactory evidence of the 

 filiation of successive forms, when the investigations of pa- 

 laeontologists are not merely actuated by the desire to dis- 

 cover geological time-marks and to multiply species, but are 

 guided by that perception of the importance of morphological 

 facts which can only be conferred by a large and thorough 

 acquaintance with anatomy and embryology. But, under 

 this aspect, the palaeontology of the Invertebrata has yet to 

 be created. 



