of size or age finds its parallel in comparative anatomy, in the general law that the larger the animal the less is the relative weight of the brain.
| Weight of entire animal gms. | Weight of brain gms. | Ratio | |
|---|---|---|---|
| Marmoset | 335 | 12ôñ5 | 1ã₤:ã₤26 |
| Spider monkey | 1845 | 126ãã | 1ã₤:ã₤15 |
| Felis minuta | 1234 | 23ôñ6 | 1ã₤:ã₤56 |
| F. domestica | 3300 | 31ãã | 1ã₤:ã₤107 |
| Leopard | 27,700 | 164ãã | 1ã₤:ã₤168 |
| Lion | 119,500 | 219ãã | 1ã₤:ã₤546 |
| Elephant | 3,048,000 | 5430ãã | 1ã₤:ã₤560 |
| Whale (Globiocephalus) | 1,000,000 | 2511ãã | 1ã₤:ã₤400 |
For much information on this subject, see Dubois, ãAbhûÊngigkeit des Hirngewichtes von der KûÑrpergrûÑsse bei den SûÊugethieren,ã Arch. f. Anthropol. XXV, 1897. Dubois has attempted, but I think with very doubtful success, to equate the weight of the brain with that of the animal. We may do this, in a very simple way, by representing the weight of the body as a power of that of the brain; thus, in the above table of the weights of brain and body in four species of cat, if we call W the weight of the body (in grammes), and w the weight of the brain, then if in all four cases we express the ratio by W =ã₤wÿ£¢nã₤, we find that n is almost constant, and differs little from 2ôñ24 in all four species: the values