PEDIGREES AND FAMILY TIES. 209 



bones. In the embryo they are undoubtedly 

 separate. 



In the wing of archceopteryx fusion or welding 

 of these bones was probably never completely 

 effected, a trace of the separate elements always 

 remained. We say probably, because there is 

 nothing to show conclusively that the two fossils 

 of archceopteryx were really those of perfectly 

 adult birds. 



It is extremely significant that the form of the 

 wing and leg of a bird so ancient as archseop- 

 teryx should so closely resemble those of modern 

 birds. The wing-bones diff"er only in the great 

 size of the claw of the third digit, for a minute 

 claw has been found in the wing of the young 

 ostrich. The leg is apparently in no way 

 peculiar. Hence we must wait for the dis- 

 covery of a yet more ancient bird before wo 

 can find out exactly from what form of a hand 

 and foot the joresent has been evolved. 



The possession of feathers so perfect in their 

 development is also wonderful. It shows us that 

 ancient as is this fossil, w^e must go yet further 

 back in time for a hint as to the beginning of 

 these feathers. The wing-feathers in their 

 number and development are as complete as 

 in many living birds, while their form and size 

 would indicate that the power of flight was 

 limited. 



The possession of a permanent claw on the third 

 digit has been a great stumbling-block to many 

 who have studied the fossil. It was taken for 

 granted that its presence was a proof that the 

 w^hole hand was used in climbing among the 

 



