FORAMINIFERA. 15 



both on the surface of the sea and also on the bottom, even at a depth of 

 J2,ooo feet From these great depths they are procured by soundings ; the 

 sounding-lead, after being coated with grease, brings up attached to it the small 

 particles with which it comes in contact Numerous such soundings were 

 taken by Sir James Ross in his Antarctic expedition, and have been practised 

 by others in different regions. Dr. Barclay records the results of a series of 

 deep-sea soundings made in the Atlantic, over a considerable geographical 

 area, from latitude 42" 4' to latitude 54 I/, at depths varying from 1/380 to 

 2,000 fathoms. " None of the soundings contain a particle of gravel, sand, or 

 other unorganized matter. They all agree hi being made up entirely of the 

 shells of Foraminifera."' There is, therefore, little doubt that the bottom of the 

 ocean is in many localities covered, perhaps to considerable depths, by a sedi- 

 mentary deposit, consisting principally of shells of this description, and which, 

 were they raised to the surface, would constitute thick beds of incalculable 

 exit 



In a fossil condition, the shells of the Foraminifera enter largely into the 

 composition of the crust of the earth in every part of the world. They form 

 by far the most important constituent of chalk wherever that substance is met 

 with. Dr. Barclay speaks of them as importantly concerned in the formation 

 of the tertiary rocks of South Carolina, and adds, u they are still at work in 

 countless thousands on that coast, filling up harbours, forming shoals, and 

 depositing their shells to record the present state of the sea-shore as their pre- 

 decessors, now entombed beneath Charlestown, have done with regard to 

 ancient oceans." 



In many parts of the world the accumulation of these shells has given origin 

 to widely-extended strata, many hundreds of feet in thickness. Mountains of 

 Nummulitic limestone, entirely composed of them, extend through the Alps 

 and Northern Italy, and are met with in Greece, Syria, and Northern India. 

 The Mokkadam range, from which the stone used' in building the Pyramids 

 was obtained, are simply masses of foraminiferous shells. According to M. 

 Deshayes, there is found in most of the stone from which Paris is built, as 

 large a proportion of the shells of Foraminifera as of particles of sand, so that 

 it may be said, almost without exaggeration, that even Paris owes the materials 

 of which it is constructed to the persistent agency of these microscopic or- 

 ganisms. 



Thus we perceive a film of living slime for such essentially these creatures 

 seem to be, moulded into a thousand beauteous forms, labouring incessantly 

 has silently produced results on which we can but gaze with awe. 



CHAPTER III. 

 SPONGES.* 



* I "HERE seems to be little relationship between the Forami- 

 JL nifera we have just been speaking of and the race of 



* Spongia, a sponge. 



