NARRATIVE OF THE CRUISE. 
841 
both before and after being treated with spirit or glycerin. It appears to occupy no 
definite position in the chambers, being sometimes found in the larger and sometimes in 
the smaller ones. Cells about 0'05 mm. in diameter, having in the interior minute 
vibrating particles, were frequently observed, but whether these were connected with the 
reproduction of the animal or not it is impossible to say. 
Pelagic Foraminifera swarm in the surface and subsurface waters of the tropics, 
where the greatest number of species and largest and thickest shelled specimens are 
found ; in the colder waters north and south, 
the specimens become smaller, till in the Arctic 
and Antarctic only dwarfed specimens of Globi- 
gerina bulloides are met with. The distribution 
of the dead shells on the bottom of the ocean 
corresponds with the distribution of the living 
ones on the surface, and is governed by surface 
temperature ; on the other hand those species of 
Foraminifera which live on the bottom attached 
to Zoophytes and other animals or substances 
have a distribution quite independent of surface 
temperature. Independently of the evidence 
afforded by the distribution of the shells above 
referred to, it is most unlikely that the same 
animals should live on the bright sunny surface 
waters at a temperature of from 60° to 80° and 
also at the bottom at a temperature of from 32° Fig. 310 . — Orbulina universa (d’Orbigny), from the deposits, 
to 40°, where there is a pressure of two or three 
miles of water and an absence of sunlight, and no living specimen of these pelagic species 
was taken on the bottom. 
These Foraminifera appear to be truly pelagic animals, and to flourish in the open sea 
far from land. It is a remarkable fact that they generally disappeared from the tow-net 
gatherings as land was approached and where river water entered the sea. They were 
very rarely taken in any of the bays or estuaries. About the British coasts, or even in the 
North Sea, they are very rarely observed, yet they are taken in great numbers on the 
surface 100 miles west of the Outer Hebrides. 
The same species inhabit the tropical waters of the Atlantic, Pacific, and Indian 
Oceans, but some species are relatively more abundant in one ocean than in another. For 
instance, Pullenia obliquiloculata is much more abundant in the Pacific than in the 
Atlantic, while Pulvinulina menardii and Sphceroidina dehiscens predominate in the 
latter ocean. 
The sarcode of the bottom-living Foraminifera was frequently examined ; that in the 
