HARDWICKE'S SCIE N CE-GO S S IP. 



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sand," but on examining the sandy particles with 

 the microscope, they were found to consist almost 

 without exception of the casts of foraminifera in one 

 of the complex silicates of alumina, iron, and potash, 

 probably some form of glauconite. The genera 

 principally represented by these casts were Miliola, 

 Biloculina, Uvigerina, Planorbulwa, Rotalia, Textu- 

 laria, Bulimina, and Nummiilina ; Globigerbia, 

 Orbulina, and Pulvinulina were present, but not 

 nearly in so great abundance. There were very few 

 foraminifera on the surface of the sea at the time. 

 This kind of bottom has been met with once or 

 twice before ; but it is evidently exceptional, de- 

 pending upon some peculiar local conditions. 



From the Cape, as far south as our station in lat. 

 46° 16', we found no depth greater than 1,900 

 fathoms, and the bottom was in every case " Globi- 

 gerina ooze " ; that is to say, it consisted of little 

 else than the shells of Globigerina, whole, or more 

 or less broken up, with a small proportion of the 

 shells of Pulvinulina and of Orbulina, and the spines 

 and tests of radiolarians and fragments of the 

 spicules of sponges. Mr. Murray has been paying 

 the closest attention since the time of our depar- 

 ture to the question of the origin of this calcareous 

 formation, which is of so great interest and import- 

 ance on account of its anomalous character and its 

 enormous extension. Very early in the voyage he 

 formed the opinion that all the organisms entering 

 into its composition at the bottom are dead, and 

 that all of them live abundantly at the surface and 

 at intermediate depths over the Globigerina-ooze 

 area, the ooze being formed by the subsiding of 

 these shells to the bottom after death. 



This is by no means a new view. It was advo- 

 cated by the late Prof. Bailey, of West Point, 

 shortly after the discovery that such a formation 

 had a wide extension in the Atlantic. Johannes 

 Miiller, Count Pourtales, Krohn, and Max-Schultzc, 

 observed Globigerina and Orbulina living on the 

 surface ; and Ernst Hseckel, in his important work 

 upon the Radiolaria, remarks that " we often find 

 upon, and carried along by the floating pieces of 

 seaweed which are so frequently met with in all 

 seas, foraminifera as well as other animal forms 

 which habitually live at the bottom." However, 

 setting aside these accidental instances, certain 

 foraminifera, particularly in their younger stages, 

 occur in some localities so constantly and in such 

 numbers, floating on the surface of the sea, that the 

 suspicion seems justifiable that they possess, at all 

 events at a certain period of their existence, a 

 pelagic mode of life, differing in this respect from 

 most of the remainder of their class. Thus Midler 

 often found in the contents of the surface- net off 

 the coast of Prance the young of Rotalia, but more 

 particularly Globigerinse and Orbulinse, the two 

 latter frequently covered with fine calcareous tubes, 

 prolongations of the borders of the fine pores through 



which the pseudogradia protrude through the shell. 

 I took similar Globigerina? and Orbulinse almost 

 daily in a fine net at Messina, often in great 

 numbers, particularly in February. Often the shell 

 was covered with a whole forest of extremely long 

 and delicate calcareous tubes projecting from all 

 sides, and probably contributing essentially to enable 

 these little animals to float below the surface of the 

 water by increasing their surface greatly, and con- 

 sequently their friction against the water, and 

 rendering it more difficult for them to sink. In 

 1865 and 1S66 two papers were read by Major 

 Owen, P.L.S., before the Linnean Society, "On the 

 Surface Fauna of Mid-Ocean." In these com- 

 munications the author stated that he had taken 

 foraminifera of the genera Globigerina and Pulvinu- 

 lina, living, in the tow-net on the surface, at many 

 stations in the Indian and Atlantic Oceans. He 

 described the special forms of these genera which 

 were most common, and gave an interesting account 

 of their habits, proposing for a family which should 

 include Globigerina, with Orbulina as a sub-genus, 

 and Pulvinulina, the name Colymbitse, from the 

 circumstance that, like the Radiolaria, these fora- 

 minifera are found on the surface after sunset, 

 " diving" to some depth beneath it during the heat 

 of the day. Our colleague, Mr. Gwyn Jeffreys, 

 chiefly on the strength of Major Owen's papers, 

 maintained that certain foraminifera were surface 

 animals, in opposition to Dr. Carpenter and my- 

 self. I had formed and expressed a very strong 

 opinion on the matter. It seemed to me that the 

 evidence was conclusive that the foraminifera which 

 formed the Globigerina ooze lived on the bottom, 

 and that the occurrence of individuals on the sur- 

 face was accidental and exceptional ; but after going 

 into the thing carefully, and considering the mass 

 of evidence which has been accumulated by Mr. 

 Murray, I now admit that I was in error ; and I 

 agree with him that it may be taken as proved that 

 all the materials of such deposits, with the excep- 

 tion, of course, of the remains of animals which we 

 now know to live at the bottom at all depths, which 

 occur in the deposit as foreign bodies, are derived 

 from the surface. 



Mr. Murray has combined with a careful examin- 

 ation of the soundings a constant use of the tow- 

 net, usually at the surface, but also at depths of 

 from ten to one hundred fathoms ; and he finds the 

 closest relation to exist between the surface fauna 

 of any particular locality and the deposit which is 

 taking place at the bottom. In all seas, from the 

 equator to the polar ice, the tow-net contains Globi- 

 gerina;. They are more abundant and of a larger 

 size in warmer seas ; several varieties, attaining a 

 large size and presenting marked varietal characters, 

 are found in the intertropical area of the Atlantic. 

 In the latitude of Kerguelen they are less numerous 

 and smaller, while further south they are still more 



