164 Tlioinas I Icnr)- Iluxlcy 



in size and weight. A fnll-grown gorilla is nearly 

 twice as heavy as a luiropean woman, and yet the 

 heaviest known gorilla brain probal:)ly does not exceed 

 twenty ounces in weight, while healthy adult human 

 brains probably never weigh less than thirty-one or 

 thirty-two ounces. This difference is not of systematic 

 importance ; for cranial capacities shew that relatively 

 and absolutely there is a greater difference in brain- 

 weight between the lowest and highest human beings 

 than there is between the highest ape and the lowest 

 human being. 



In dealing with the suggestion that man differs from 

 the apes in being bimanous, while the apes are quadru- 

 manous, Huxley first explained and discussed what the 

 exact differences between hands and feet are. He 

 shewed that in man the foot is absolutely distinguished 

 from the hand b}^ three structural points, although the 

 two organs are similar in general ground-plan. These 

 structural points are : 



1. The arrangement of the tarsal bones. 



2. The possession of a short flexor and short extensor 

 muscle of the digits. 



3. The possession of a muscle named peronceus 

 lonous. 



Then he described the foot of the gorilla, and shewed 

 that although it was superficially hand-like, it possessed 

 all the structural characters that distinguish a foot from 

 a hand. Tracing the structure of the foot downwards 

 through the .series of anthropoids and monkeys, he 

 established clearly that, while important differences 

 existed in nearly every single creature, the differences 

 between the gorilla and man were not greater than 

 those between the gorilla and other anthropoids, and 

 less than between the gorilla and lower monkeys. 



