MACDONALD'S RESEARCHES. 149 



depths of ocean in these antipodean regions, as was 

 recorded in the northern half of the Atlantic ; and 

 especially when, as was the case, results exactly 

 similar were yielded by the casts obtained from the 

 icy seas of Kamtchatka and Behr ing's Straits. Here, 

 too, the deposits are wholly siliceous, and are princi- 

 pally rich in the remains of the Diatomacece. 



While these results were being obtained with the 

 newly-invented sounding apparatus of Brooke, H.M.S. 

 Herald was engaged on a surveying cruise in the 

 Pacific ; and her surgeon, Mr Macdonald, an accom- 

 plished naturalist, was pursuing similar investigations 

 of the deep-sea bottom. He found the Foraminifera 

 in very considerable abundance in the vicinity of the 

 Fiji Islands, at a depth of upwards of six thousand 

 feet ; and, what is a fact of great interest in connexion 

 with these vast burial-grounds, he observed consider- 

 able numbers of the living animalcules adhering to 

 the fronds of the smaller marine Algse, either floating 

 on the surface of the ocean, or growing on the shores 

 of the Pacific Islands ; so that the abundant appear- 

 ance of the dead shells of these tiny animals in the 

 sand of every beach, and in every sea-bottom fathomed 

 by the armed lead, was satisfactorily accounted for. 

 How inconceivably numerous these remains of animal 

 life really are in the sands of the shore, may be esti- 

 mated from the fact, in addition to that already men- 

 tioned, that in some beach-sands upwards of half of 

 the entire bulk is composed of these microscopic 

 shells. Plancus counted six thousand in an ounce of 



