I termed these bodies "coccoliths," and doubted their organic nature.

Dr. Wallich verified my observation, and added the interesting discovery that, not unfrequently, bodies similar to these "coccoliths" were aggregated together into spheroids, which lie termed "coccospheres."

Comparing these formed particles with those in the Atlantic soundings, he found the two to be identical; and thus proved that the chalk, like the surroundings, contains these mysterious coccoliths and coccospheres.

Globigerinoe, coccoliths, and coccospheres are found as the chief constituents of both, and testify to the general similarity of the conditions under which both have been formed.

[Footnote 3: I have recently traced out the development of the "coccoliths" from a diameter of 1/7000th of an inch up to their largest size (which is about 1/1000th), and no longer doubt that they are produced by independent organisms, which, like the Globigerinoe, live and die at the bottom of the sea.]

As I have pointed out elsewhere, it at once became obvious that the calcareous sticky mud of the Atlantic was made up, in the main, of shells of Globigerina and other Foraminifera, identical with those of which the true chalk is composed, and the identity extended even to the presence of those singular bodies, the Coccoliths and Coccospheres, the true nature of which is not yet made out.

What if Globigerina and the Coccoliths should not be the only survivors of a world passed away, which are hidden beneath three miles of salt water?

The smaller Foraminifera now give way, and are found in lessening proportion to the larger; the coccoliths first lose their thin outer border and then disappear; and the clubs of the rhabdoliths get worn out of shape, and are last seen, under a high power, as infinitely minute cylinders scattered over the field.