250' Remarks on Marine 



were examined, and more particularly respecting their powers 

 of yielding light. If there is any deficiency in the nature of this 

 proof, as it relates to some of the more minute animals, there 

 will still remain a considerable number to add to the list 

 formerly given. 



It must in the first place be remarked, that the whole of these 

 observations were confined to spaces in the sea never extending 

 above 8 or 10 miles from land; and that they were very generally 

 made in harbours. They cannot in fact be made at sea ; at 

 least in a small ship, unless it is smooth water: as the agitation 

 of the water under examination, no less than that of the ob- 

 server's person, renders it absolutely impossible to catch and 

 detain the objects before a lens in such a manner as to examine 

 or delineate them. At all times, even in harbour, it is suffi- 

 ciently difficult from the motions of the animals themselves, to 

 obtain^i^^ch views of them as to satisfy ourselves respecting the 

 nature and characters of those which are minute, and of which 

 the greater number are exceedingly restless and rapid in their 

 movements. 



Although a great many of the animals which fell under my 

 notice, were found at the distances from land which I have just 

 mentioned, many were only discovered in harbours, and, nearly 

 at all times they were far more abundant in these situations than 

 in the open sea. Some of them, it is true, seem to disregard 

 boisterous weather; but there were many which almost invari- 

 ably disappeared on the coming in of a fresh gale, and only re-ap- 

 peared when the weather moderated. Other changes of weather 

 or wind, often caused them in the same manner to disappear in 

 the course < f a few hours. It is probable that these animals, 

 like the leech, are very sensible to atmospheric changes, and 

 that they retire to deeper water to avoid that agitation, which, to 

 many of the larger, would be fatal, from the tenderness of their 

 texture and from their bulk. Many are probably destroyed by 

 the violence of the sea at the surface. These are hints which 

 may be of use to any naturalist inclined to enter on this de- 

 partment of his pursuit, while they assist in explaining the 

 variations to which the luminous property of the ocean is sub- 



