170 The Naturalist of Cumbrae. 



" Nothing seems more wonderful to me than the 

 power many of these animals have of changing place ; 

 and no way have I seen this so well exemplified as 

 in the take of the surface-net, and particularly after 

 night-fall, when I meet with amphipods, isopods, 

 cumas, and annelids, in very great abundance, saying 

 nothing of the smaller larval forms that often, from 

 their numbers, colour the sea by day and illuminate 

 it by night. I meet with them on the surface from 

 the shallow shore to over a depth of seventy fathoms, 

 many of them characteristic of mud, sand, and gravel 

 bottom habitats. How the annelids and many others 

 wriggle up through such depths is difficult to con- 

 ceive. In the commotion of tides and winds many of 

 them must be often carried far from their particular 

 homes ; and the question rises broadly before us, can 

 they unerringly in ordinary cases regain their par- 

 ticular habitats, or do most of these nightly wanderers 

 perish by the way when they fail in that endeavour?" 



This is not the place fully to discuss the question 

 here propounded, but it may be observed, first, that 

 many of the little marine animals have motions 

 extremely rapid in proportion to their size ; secondly, 

 that time is within moderate limits no object to them ; 

 thirdly, that, the conditions being similar, they can 

 mostly make themselves at home as well in one spot 

 as in another, even if in the morning they should 

 descend to a flat of sand or bed of sea-weed at a mile 

 or miles away from that which they quitted overnight. 

 But, on the other hand, it is clear that the overwhelm- 

 ing numbers, which would result from the prodigious 



