EMOTIONS. 349 



different localities. Now, as tliis manoeuvre requires a long 

 time to execute, I think the fact that after it has been 

 executed the animal continues its advance in the same direc- 

 tion as that in which it was crawling before the manoeuvre 

 began, constitutes tolerable evidence in favour of an abiding 

 impression upon the nerve-centres concerned, and one wliich 

 assuredly is not due to any organically imposed conditions, 

 seeing that on no two occasions is the manoeuvre performed 

 in exactly the same way, or even at the same intervals of 

 time. 



On the next level I have placed Larvae of Insects and 

 Annehda. My reason for doing so is that both these classes 

 of organisms unquestionably exhibit instincts of the primary 

 kind,* the origin of which is also assigned to this level. In 

 both cases, however, we meet with certain facts which may 

 justly lead us to question whether in these animals intelli- 

 gence of a higher order may not be present ;t but here again 

 I think it is better to err on the safer side. 



It is in the Mollusca that we first undoubtedly meet with 

 a demonstrable power of learning by individual experience,! 

 and therefore I have placed this class of animals upon the 

 next level, which is occupied by the first appearance of the 

 power of association by contiguity. Of course, if the account 

 given by Mr. Lonsdale to Mr. Darwin of the pair of land- 

 snails § were ever to be corroborated by further observations, 

 the Gasteropoda would require to be separated from the 

 other Mollusca and placed on a higher level in the diagram, 

 as I have done in the case of the Cephalopoda. 



Next we come to Insects and Spiders on a level with the 

 first Eecognition of Offspring and the rise of Secondary 

 Instincts. The evidence that both these faculties occur in 

 both these divisions of the Articulata is unquestionable — 

 and this even when the Hymenoptera are removed for 

 separate psychological classification. || 



Fish and Batrachia are assigned to the next level which 

 corresponds with the rise of Association by Similarity, which 

 I think we are justified in first ascribing to these animals.lF 



On level 22 I have written the higher Crustacea. I 



* See Animal Intelligence, 234-40, and 24. 



t Hid., and Mr. Darwin's work on Worms. 



X Ibid., pp. 25-©. § Ibid., p. 27. 



II Ibid., pp. 207-222, and 226-31. H Ibid., pp. 250-1, and 255. 



