HOMOLOGY. 



47 



haps, may be more properly regarded as example's of " vege- 

 tative repetition " of parts than as being instances of true 

 serial homology. This is, at any rate, certainly the case 

 with the flattened segments which make up the great bulk 

 of what is ordinarily called a "tapeworm," and which are 

 produced as genuine buds from a rounded " head," which 

 they in no way resemble either in structure or in function. 



In Vertebrate animals serial homology is a much less 

 evident phenomenon than in the cases we have been con- 



Fig. 16. Fore-limb of Chimpanzee (after 

 Owen).t h Humerus ; r Radius; u 

 Ulna ; d Bones of the wrist, or carpus; 

 in Metacarpus ; p Phalanges of the 

 fingers. 



Fig. 17. Hind-limb ot the Chimpanzee 

 (after Owen). / Femur ; t Tibia; -s 

 Fibula ; r Bones of the ankle, or tar- 

 sus; m Metatarsus; / Phalanges of 

 the toes. 



sidering, but it nevertheless exists in a well-marked form. 

 Thus the vertebral column or backbone is composed of a 



