NATURAL CARVINGS. 431 
ton may be added, consisting merely of fine pin-like masses, 
orspieula, and these may be loose or united into a solid 
shell of great beauty of form and sculpture, as our Plate 
shows, or the skeleton is an assemblage of stout rods meet- 
ing in the middle of the creature, where a sac is found, and 
pointing in all directions. Here we see the applicability of 
the name given to the class of Radiolaria. No reproduction, 
by means of a true sexual process, has been as yet observed 
in any Radiolarian, and therefore here is opened a very 
promising and attractive field of research for the naturalist. 
For the most that is known of the Polycistines, in their 
living condition, we are indebted to Prof. Müller, a cele- 
rated German naturalist; but their remains, or shells, 
which are preserved in certain rocks in different parts of 
the world have been investigated and figured by the great 
microscopist of Berlin, Ehrenberg. He first discovered them 
in the mud brought up from the bed of the river Elbe, at 
Cuxhaven, and afterwards he found them in similar collec- 
tions made in the antarctic seas. Prof. Bailey, one of the. 
first and most enthusiastic American naturalists, also ob- 
served them, accompanied by other organisms, both animal 
and vegetable, in soundings, brought up by the lead from 
the bottom of the Atlantic Ocean, at depths of from 1000 
to 2000 fathoms. So, also, the sea-bottom which has been 
Procured from the Gulf of Mexico, off the coast of Florida, 
in some quantity, by means of a peculiar apparatus specially 
Constructed for the purpose, is seen to be extremely rich in 
Some of the more exquisite forms of these glassy shells. The 
Microscope has thus revealed the existence of an universe 
of life at the bottom of the ocean. Of course the soundings 
Made previous to the laying of the Atlantic Telegraph cable 
tol the same story ; here, as elsewhere, the sea-bed is over- 
aid with a carpet of the silicious remains of these beauteous 
atoms. During some past geological periods, however, it 
Would seem that the Polycistine existed in much greater 
humbers than at the present time, for certain strata of con- 

