CONTENTS OF A ROCK-POOL. 21 



heavy ! — lias taught, that the two conditions most favour- 

 able to most of those marine animals we are in quest of are 

 Darkness and Depth of water. They are impatient of the 

 light, and prefer -darkness even to many fathoms. When I say 

 they, I mean most Molluscs, Crustacea3, Annelids, and Zoo- 

 phytes. Jellyfish seek the light, and float at the top of the 

 sunny sea ; but we shall find none of them to-day, so that 

 fissures, caves, and the under side of boulders, must be our 

 fields. It is well for the young hunter to bear in mind this 

 requisite of darkness. Let him turn over all stones, peer 

 into all fissures, push aside the overhanging Fucus, or long- 

 waving Oar-weed, and see if the pools beneath do not con- 

 tain what he seeks. And when I say look, he must not 

 understand thereby a careless casual glance, but a long 

 deliberate scrutiny. He must allow the eye to rest long 

 enough on the spot to lose the perplexity occasioned by a 

 hundred different details, and must let " the demure travel 

 of his I'cgai'd " pass calmly over it. Sometimes the pool is 

 so dark and still, that it is not until your nose-tip is cold 

 against the surface that you know there is water. We have 

 just climbed up a ledge, and looked down into a pool. 

 Our footing is somewhat insecure, but we cling savagely, 

 and call down few blessings on the heads of the countless 

 Balance which stud the rock, and tear our hands. There, 

 now, we have settled into a jjosition in which we can work. 

 Look at that Gem, with its lovely tiger-tentacles ; it has 

 just swallowed a small fish, and is now, while digesting, 

 opening its arms for more. And there, on the green broad 

 leaves of the Ulva, crawl two Sea Hares (Aplysice). (See 

 Plate IL, fig. 4.) What queer creatures ! One would fancy 



