58 ANIMAL INSTINCT AND INTELLIGENCE 



traversed being often very irregular and covered with acorn- 

 barnacles. When the animal gets back to the scar it of course 

 arrives wrong way on, so to speak, and it quickly shuffles round 

 so as to get into the proper position. A memory of locality 

 certainly exists, and this would seem to imply intelligence. In 

 the course of time a Limpet acquires a very accurate knowledge 

 of the topography of a fair-sized area around its home, and if 

 picked up when on the crawl and placed .within this area is able 

 to get home, though the time taken varies considerably. Exactly 

 how it gets home we do not know. The simple cup-like eyes- 

 cannot render assistance, nor can we very well suppose that the 

 otocysts help to guide it. Experiments appear to demonstrate 

 that the animal does not smell its way back, and we are there- 

 fore reduced to touch, or to a ''locality sense", or to both. The 

 most obvious organs of touch are the two large tentacles on 

 the head, with which the Limpet constantly touches the rock as 

 it crawls, and it is no doubt by means of these that a good 

 deal of the topographical knowledge is acquired. But as it can 

 get home without the aid of these organs there must be some 

 other organs of guidance. The edge of the mantle-flap is pro- 

 vided with a very large number of small tentacles which can be 

 stretched out and actively moved, as they are sometimes, if not 

 always, when the animal is adjusting itself on its scar. These 

 perhaps have something to do with the matter, and so may still 

 other sense-organs, but further investigation is required. The 

 problem here to be solved, like most of those connected with 

 locality-knowledge, is of a particularly baffling kind, though not 

 to be regarded as insoluble. The Garden- Snail (Helix asperse?) is 

 another Mollusc possessed of a "homing instinct" 



INSTINCT AND INTELLIGENCE IN VERTEBRATES 



(VERTEBRATA) 



There is here an almost unlimited amount of material which 

 might be discussed, but a few examples must suffice. 



WARNING COLORATION. A large number of animals pos- 

 sessed of noxious properties advertise their objectionable nature 

 by means of bright though somewhat crude colours, and simple 

 but striking patterns, the net result of which is to render 

 them extremely conspicuous (see vol. ii, p. 301). Such are the 



