ASSOCIATION OF IDEAS. 123 



for a great number of times, till all the tentacles had been 

 progressively cut away little by little. Yet the animal never 

 learnt to associate the appearance of the scissors with the 

 effect which always followed it, and so never drew in until 

 the snip had been given. Nevertheless, that memory does 

 occur among the higher Crustacea is proved by an observation 

 quoted in "Animal Intelligence" (p. 233), concerning a 

 lobster mounting guard upon a heap of shingle beneath which 

 it had previously hidden some food. 



In another class of the Articulata, however, the faculty of 

 memory has been developed to an extraordinary degree, and 

 far surpasses that which has been attained by any other class 

 of Invertebrata. The class of the Articulata to which I allude 

 are the Insects, and, more particularly, the Hymenoptera. 

 Without quoting in extenso the evidence on this head which 

 has already been given in my previous work, it is enough to 

 say in general terms that ants and bees are unquestionably 

 able to remember the places wdiere many months before they 

 have obtained honey or sugar, &c. ; and will also, when 

 occasion requires, return to nests and hives which they have 

 deserted the year before. Many interesting observations have 

 also been made on the rate of acquisition and the length or 

 duration of particular memories in these animals, which, 

 however, it is needless for me again to quote.* Perhaps the 

 most interesting of these are the observations of Sir John 

 Lubbock on bees gradually learning to know the difference 

 between an open and a closed window, and the observations 

 of Messrs. Bates and Belt on the sand- w^ asps carefully teach- 

 ing themselves (by taking mental notes of landmarks) the 

 localities to w^hich they intend to return in order to secure 

 the prey which they have temporarily concealed. Incidental 

 evidence of memory in other orders of Insects will also be 

 found on referring to my previous w^ork — viz., for Beetles, 

 pp. 227 — 9, for Earwigs, p. 229, and for the common House- 

 ^y, p. 230. 



Turning now to the Vertebrata, we find that in Fish 

 memory is certainly present, although it never reaches more 

 than such a degree of development as is implied by remem- 

 bering in successive years the locality for spawning, learning 

 to avoid baits, removing young from a nest which has been 



* For a full account of all these observations, see Animal Intelligence^ 

 under the heading " Memory," of Chap. Ill and IV. 



