74 THIRD GENERAL MEETING. 



Since 1876, when Huxley visited me at New Haven, and we 

 discussed the probable origin of both Birds and Mammals, I have 

 been greatly impressed by his suggestion that the mammals were 

 derived from ancestors with two occipital condyles, and these were 

 doubtless primitive Amphibians. I have since sought diligently 

 for the ancestors of birds among the early reptiles, with, I trust, 

 some measure of success, but this is a simple problem compared 

 with the origin of mammals which we have before us to-day. 



In various interviews with Francis Balfour, in 1881, at the York 

 Meeting of the British Association, we discussed the same questions, 

 and agreed that the solution could best be reached by the aid of 

 Embryology and Paleontology combined. He offered to take up 

 the young stages of recent forms, and I agreed to study the fossils 

 for other evidence. His untimely death, which occurred soon after, 

 prevented this promised investigation, and natural science still 

 suffers from his loss. Had Balfour lived, he might have given us 

 to-day the solution of the great question before us, and the present 

 discussion would have been unnecessary. 



The Birds like the mammals have developed certain characters 

 higher than those of reptiles, and thus the two classes seem to 

 approach each other. I doubt, however, if they are connected 

 genetically, unless in a very remote way. 



Reptiles, although much lower in rank than birds, resemble 

 mammals in various ways, but this may be only an adaptive 

 likeness. Both of these classes may be made up of complex groups 

 only distantly related. Having both developed along similar lines, 

 they exhibit various points of resemblance that may easily be 

 mistaken for indications of real affinity. 



In the Amphibians, especially in the oldest forms, there are 

 hints of a true relationship with both Reptiles and Mammals. It 

 seems to me, therefore, that in some of the minute primitive forms, 

 as old as the Devonian, if not still more ancient, we may yet find 

 the key to the great mystery of the Origin of Mammals. 



Professor Haeckel said that he had discussed the problem 

 with Huxley and Lyell 32 years before, and the former then 

 strongly held the poh'phyletic origin of the placental mammals, 

 the carnivorous and herbivorous groups having descended re- 

 spectively from carnivorous and herbivorous marsupials. This 

 view was now untenable, and the speaker believed that the 

 different series of placental mammals converge so nearly that they 

 must have all been derived from one marsupial ancestor. 



Mr Sedgwick called attention to the fact that embryology, 

 which had been appealed to by previous speakers to assist in the 

 solution of the problem, in reality gave very little, if any, light. 

 With regard to organs, which on the ordinary view of evolution, 

 must have been recently altered, such as the wings of birds, limbs 



