ORGANIC EVOLUTION — MENTAL 151 



shut, and then live for a much longer time when taken 

 out of the water." — Animal Intelligence, p. 25. 



"These animals (snails) appear also susceptible of 

 some degree of permanent attachment. An accurate 

 observer, Mr. Lonsdale, informs me that he placed a 

 pair of land-snails {Helix iwmatia), one of which was 

 weakly, into a small and ill-provided garden. After a 

 short time the strong and healthy individual dis- 

 appeared, and was traced by its track of slime over a 

 wall into an adjoining well-stocked garden. Mr. Lons- 

 dale concluded that it had deserted its sickly mate ; but 

 after an absence of twenty-four hours it returned, and 

 apparently communicated the result of its successful 

 exploration, for both then started along the same track, 

 and disappeared over the wall." — Descent of Man, pp. 

 262, 263, quoted by Professor Romanes in Animal 

 Intelligence, p. 27. 



Both the oyster and the snail appear capable of 

 acting, in however limited a degree, by virtue of 

 acquired knowledge. That some insects possess this 

 power to a great extent is evident from the fact that 

 enslaved ants acquire mental traits vastly different 

 from those exhibited by the free members of the same 

 species. It should be noted that adult ants are never 

 enslaved, the pupae alone being carried off, so that 

 whatever traits the slaves acquire are acquired under 

 the tuition of their masters. 



"When the pupse hatch out in the nest of their 

 captors, the young slaves begin their life of work, and 

 seem to regard their master's home as their own; for 

 they never attempt to escape, and they fight no less 

 keenly than their masters in defence of the nest. 

 F. sanguinea content themselves with fewer slaves than 

 the F. rnfcsccns ; and the work that devolves upon 



