156 EVOLUTION AND MAN S PLACE IN NATURE 



self. Again, inasmuch as the dog has a prominent 

 olfactory lobe, outstretching the frontal lobes of the 

 brain, and has greatly more acute sense of smell than 

 we have, we assign to him superiority to man in this 

 phase of sensory experience. Thus, when sensory 

 structure becomes the test of comparison, cross classi 

 fications are inevitable, involving collateral issues. It 

 is impossible to distribute capacity of sensibility in 

 accordance with an animal s position in the scale of 

 animate existence. Great differences in structure of 

 sensory organs, and consequently in sensible experi 

 ence, appear at various points. The examples given 

 are conclusive. With this is included the inference, 

 that increased sensibility bears no testimony for in 

 telligence. Power of discrimination by means of 

 apparatus, cannot support an inference in favour of 

 the existence of intelligent discrimination. Sensibility, 

 even though it be superior to that of humanity, does 

 not of itself imply power of that higher kind which 

 we attribute to the higher mammals. The superiority 

 of touch belonging to the ant, in comparison with 

 that belonging to the dog, is manifest. On the other 

 hand, evidence for intelligence in the dog is obtained 

 by external observation. It is connected mainly with 

 the animal s interpretation of signs, as when the collie 

 extends his run at the shepherd s call. This presents 

 our first generalisation. Sensibility to contact with 

 external objects is common to &quot;all organic life on the 

 earth, and is a thing distinct from intelligence. Differ 

 ence of sensibility depends upon difference of structure, 

 and upon nothing besides. There are no data on which 

 it is possible to modify this conclusion. Morphology 

 of sensory structure does not guide to a science of 



