LIFE IN THE OCEAN. 65 



pools, left here and there by the retiring tide, are dragged by nets of 

 very small mesh, in which the smaller crustaceous mollusks and small 

 fish are secured." 



In the Mediterranean and other inland seas, where the tide is 

 almost inappreciable, there exist a great number of animals and 

 vegetables belonging to the deep sea, which the waves or currents 

 very rarely leave upon the sea shore. There are others so fugitive, 

 or which attach themselves so firmly to the rocks, that we can watch 

 them only in their habitats. It is necessary to study them floating 

 on the surface of the waves, or in their mysterious retirements. Hence 

 the necessity that naturalists should study the living productions of the 

 salt water even in the bosom of the ocean, and not on the sea shore. 



The means generally employed for this purpose is a drag-net, 

 sounding-line, and other engines suitable for scraping the bottom, and 

 breaking the harder rocks. In a voyage which Milne Edwards made 

 to the coast of Sicily, he formed the idea of employing an apparatus 

 invented by Colonel Paulin, which consisted of a metallic casque pro- 

 vided with a visor of glass, and consequently transparent, which fixed 

 itself round the neck by means of a copper collar made water-tight by 

 stuffing a diving-bell, in short, in miniature. It communicated with 

 an air-pump by means of a flexible tube. Four men were employed 

 in serving the pump, two exercising it while the other two rested 

 themselves. Other men held the extremity of a cord, which was 

 passed over a pulley attached at a higher elevation, and enabled them 

 to hoist up the diver with the necessary rapidity in emergencies. A 

 vigilant observer held in his hand a small signal cord. The immersion 

 of the diver was facilitated by heavy leaden shoes, which assisted him at 

 the same time to maintain his vertical position at the bottom. 

 M. Edwards made the descent with this apparatus in three fathoms 

 water with perfect success. He was thus enabled to study, in their 

 most hidden and most inaccessible retreats, the radiate animals, 

 mollusks, crustaceans, and annelids, especially their larvss and eggs, 

 and by his descriptions to contribute most essentially to make known 

 the functions, manners, and mode of development of certain inhabitants 

 of the sea, whose sojourn and habits would seem to sequestrate them 

 for ever from our observation. 



Another and easier mode of studying the living creatures sheltered 



r 



