The process carrying the otolith outer side of a or concretion hk, formed by endoderm cells, is tentacle, two enclosed by an upgrowth forming the " vesicle," nerves run round which is not yet quite closed in at the top. the base of the (After Hertwig.) tentacle to it.
In his Sylva sylvarum (1627), Francis Bacon states that " the original concretion of bitumen is a mixture of a fiery and watery substance," and observes that flame " attracts " the naphtha of Babylon " afar off."
Whilst pyrites is found abundantly in the older crystalline rocks and slates, marcasite is more abundant in clays, and has often been formed as a concretion around organic remains.
Here the Cambrian system is only distinguished clearly on the eastern side, where the three subdivisions are found in a thin series of strata (400 ft.), in which black concretion-bearing shales play an important part.
This substance, which has been found to be a purely siliceous concretion, is possessed of peculiar optical properties.
The substance called "ambergris," formerly used in medicine and now in perfumery, is a concretion formed in the intestine of this whale, and found floating on the surface of the sea.
Con, Endodermal concretion continued into the tentacuthe hood.