32 ANNUAL REPORT OF 



statement. Let us imagine the evidence of fossils to be excluded ; 

 and let the zoologist, whom we may suppose is acquainted only 

 with the modern fauna, be required to frame a theory of evolu- 

 tion. He will at once perceive that animals belonging to- certain 

 groups resemble one another more or less closely, but the groups 

 themselves are widely separated; and, moreover, in some of them 

 there exist wide gaps without any hint that they were ever filled 

 or bridged over by intermediate forms. Holding in his grasp 

 merely the ends of disconnected threads, how is the zoologist to 

 prove their continuity, how demonstrate that they have all di- 

 verged from a common strand ? Is it not equally logical for him 

 to maintain, under the assumed limitations, the doctrine of 

 special creation, and deny that the most extreme types of varia- 

 tion are linked by common ancestry? 



All the way from a quarter to half a century ago, before 

 palaeontology had made its great strides in advance, the con- 

 ditions we have imagined were altogether real, and the lacunae 

 between genera, families and higher groups presented a diffi- 

 culty which it appeared unreasonable to explain by an appeal 

 to- the imperfection of the palseontological record. On the one 

 hand the doctrine of evolution required these gaps to be filled, 

 on the other no< evidence was forthcoming to' show that they 

 ever had been filled. An interesting anecdote is related of the 

 elder Agassiz by one of his students, Professor A. S. Packard, 1 

 which illustrates the attitude or the great naturalist toward 

 evolution in his latter years. At the close of a lecture on 

 Umulus, the horseshoe crab, in which Agassiz advocated the 

 view that it does not stand as an isolated form in creation, but 

 is descended from the common stem of jointed animals, the mas- 

 ter strode up and down in a state of evident excitement, and 

 then, as Packard recalls, "remarked to us with one of his most 

 genial smiles on his lips : 'I should have been a great fellow for 

 evolution if it had not been for the breaks in the palseontological 

 record.' We replied : 'But, Professor, see what great gaps have 

 been filled by the recent discoveries of birds with teeth, and of 

 Tertiary mammals connecting widely separated existing orders.' 



1 Amer. Nat, vol. xxxii (1898), p. 164. 



