350 
POPULAR SCIENCE' REVIEW. 
WHAT IS BATHYBIUS? 
By Brofessor W. C. WILLIAMSON, F.R.S, 
D URING- each successive year the Protozoa prove to be of 
increasino- importauce to the physiologist. In no other 
class of matured animals can the protoplasm, of which we have 
recently heard so much, be studied to such advantage. Con- 
stituting the lowest known manifestation of both animal and 
vegetable life, it seems to bring us very near to the boundary 
between the organic and the inorganic worlds. It exhibits the 
simplest phenomena of life under the least complex of conditions ; 
hence it has recently been appealed to b}^ one of the most philo- 
sophical of living zoologists as capable of throwing light upon 
the most recondite of biological problems. Without accepting 
all, or even the chief of the conclusions at which Professor 
Huxley has arrived from his study of protoplasm, he must be 
deemed right in the importance which he assigns to it. Whether 
seen as the gelatinous sarcode of the Protozoa, occupying the 
base of the animal kingdom, or as the yolk-material out of which 
the embryo of the highest vertebrate is formed; — whether we 
observe its plastic mass in the primordial germ of a ProtococQUS 
or of a Volvox, or as it appears in the leaf-bud of an oak, it 
everywhere brings before us the first stage in acts of organi- 
sation in which it is the chief, if not the only actor. Neverthe- 
less, I am unable to see that our study of protoplasm has 
})rought us nearer than before to a knowledge of the origin of 
that mysterious force which converts inorganic into organised 
material. There yet remains to be bridged over that un- 
fathomed gulf which separates death from life — the most complex 
effects of inorganic forces from the simplest of vital phenomena. 
We can trace the action and development of protoplasm through 
successive generations of organisms, but, like the spot where the 
rainbow touches the ground, its mysterious origin recedes as we 
advance, and a weary chase leaves us no nearer our object than 
when we commenced its pursuit. We increase our information 
respecting the conditions of its existence, but not of its origin ; 
