620 REPOKT— 1902. 



' demonstrative evidence of the occurrence of evolution,' and that the facts of 

 palaeontology came to be regarded as certainly not second to those of the fascinating 

 but seductive department of embryology, at the time making giant strides.* 



I have endeavoured thus to picture that state of zoological science at the time 

 of our last meeting here ; and I wish now to confine myself to some of the broader 

 results since achieved on the morphological side. But let us first digress, in order 

 to be clear as to the meaning of this phrase. 



We do not expect the public to be accurate in their usage of scientific terms; 

 but it is to me an astounding fact that among trained scientific experts, devotees 

 to branches of science other than our own, there exists a gross misunderstanding 

 as to the limitations of our departments. I quote from an official report in 

 alluding to ' comparative anatomists, or biologists, as they call themselves,' and I 

 but cite the words of an eminent scientific friend, in referring to biology and 

 botany as coequal. In endeavouring to get rid of this prevailing error, let it be 

 once more said that the term ' biology ' was introduced at the beginning of the 

 nineteenth century by Treviranus and Lamarck, and that in its usage it has come 

 to signify two totally distinct things as employed by our Continental contem- 

 poraries and ourselves. By ' Biologic ' they understand the study of the organism 

 in relation to its environment. We, following Huxley, include in our term 

 biology the study of all phenomena manifested by living matter; botany and 

 zoology ; and by morphology we zoologists mean the study of structure in all its 

 forms, of anatomy, histology, and development, with palaeontology — of all, that is, 

 which can be preferably studied in the dead state, as distinct from physiology, the 

 study of the living in action. Comparative morphology, the study of likeness 

 and unlikeness, is the basis of our working classifications, and it is to the con- 

 sideration of the morphological method, and the more salient of its recent results 

 that I would now proceed, in so far as it may be said to have marked progress 

 and given precision to our ideas within the last eight-and-twenty years. 1 would 

 deal in the main with facts, with theories only where self-evident, ignoring that 

 type of generalisation to which the exclusive study of embryology has lent itself, 

 which characterises, but does not grace, a vast portion of our recent zoological 

 literature. 



To the earnest student of zoology, intent on current advance, the mental image 

 of the interrelationships of the greater groups of animal forms is ever changing, 

 kaleidoscopically it may be, but with diminishing effect in proportion as our know- 

 ledge becomes the more precise. 



Returning now to American palaeontology, we may at once continue our 

 theme. In this vast field, expedition after expedition has returned with material 

 rich and plentiful ; and while, by study of it, our knowledge of every living 

 mammalian order, to say the least, has been extended, and in some cases revolution- 

 ised, we have come to regard the Early Tertiary period as the heyday of the 

 mammals, in the sense that the present epoch is that of the smaller birds. No 

 wonder then that there should have been discovered group after group which has 

 become extinct, or evidence that in matters such as tooth-structure there is reason 

 to believe that types identical with those of to-day have been previously evolved 

 but to disappear.^ To contemplate the discovery of the Titanotheria,'" the Am- 

 blyopoda," the Dinocerata with their strange diminutive brain, '^ chief among the 

 heavier ungulate forms, is to consider the Mammalia anew ; and when it is found 

 that among late discoveries we have (1) that of a series of Rhinoceratoidea, which 

 though not yet known to extend so far back in time as the primitive tapirs and 

 horses are complete as far as they go ; " ('J) that among the Ruminants we have, in 

 the Oreodontidae of the American Eocene, primitive forms with a dentition of forty- 

 four teeth, an absence of diastemata, a pentadactyle manus, a tetradactyle pes 

 with traces of a hallux, and, as would appear from an example of Mesoreodon, a 

 bony clavicle, such as is unknown in any later ungulate, we are aroused to a pitch 

 of eager enthusiasm as to the outcome of labours now in hand ; ^^ for, as I write, 

 there reaches me a letter, to the efiect that for most of the great vertebrate groups, 

 and not the mammals alone, collections are still coming in, each more wonderful 

 than the last.^"' 



