CEABS AS TRESPASSERS. 329 



and yet the shrimps gave no sign until they came to 

 the narrow track of their food. It is possible, there- 

 fore, that the Climbing Perch may be attracted to the 

 water by a sense analogous to that which enables the 

 Crustacea to discover their prey. 



The fishes can live for five or six days without a 

 fresh supply of water, and so have plenty of time in 

 which to make their migrations. When on shore they 

 keep the gill-covers open, so that the oxygen of the 

 atmosphere can play upon them, and they only need 

 just enough of the water to keep them moist. The 

 reader will remember that several of our own fish, such 

 as the carp, can live for several days if kept in wet 

 moss. 



CRABS AS TRESPASSERS. 



I suppose that there are few, if any, of my readers 

 who have not seen living crabs and lobsters on the 

 marble slab of a fishmonger's shop ; and have, per- 

 haps, when children, been quite astonished when they 

 found that lobsters were not red until they were 

 boiled. 



Now these creatures had all been out of the sea for 

 many hours, and were yet lively and strong, as anyone 

 could testify who put his finger between their claws. 

 33 ow was it, then, that they were able to sustain life 

 under such conditions, while fish which came from the 

 sea at the same time were all dead ? This is a very 

 fair and reasonable question, and deserves a definite 

 answer. 



The reader will remember that the climbing 



