414 
ORIGINAL ARTICLES. 
into a mass or layer of the peculiar structureless histological ele¬ 
ment, which has been called “ sarcode.” This mass or layer, pos¬ 
sessing, as distinguished from the true embryo, a distinct indivi¬ 
duality, and performing its functions entirely and maturely while the 
rudimentary tissues of the embryo are being laid down. 
I cannot agree with Prof. Carpenter, Prof. Schultze, and others, 
that “ sarcode” is simply equivalent to protoplasma, or elaborated 
organic pabulum. It undoubtedly possesses special vital properties, 
and is capable, without the intervention of any accessory organization, 
of performing active vital functions. To take an example. The auri- 
cularian pseudembryo of a Holothuria is formed entirely of this abso¬ 
lutely structureless material, but, according to its special develop¬ 
mental law, calcareous spiculse, and wheels of complex form, are 
produced imbedded in its substance—at first, a minute closed hollow 
calcareous particle appears, imbedded in the transparent sarcode; 
this gradually lengthens, enlarges, and assumes a complicated form. 
How is this effected P The calcareous particles themselves are, of 
course, utterly inert. It can scarcely be said that the calcareous 
tube enlarges itself by resorbing its own walls and adding to them. 
It is equally inconceivable that the power of re-arrangement exists in 
the infinitesimally divided organic matter, combined with the lime 
in the wall, if there be any such. The wall must be built from the 
outside by an external agent, and an agent of great vital activity. 
Again, the calcareous matter is derived from the sea-water in which it 
exists in the form of an almost infinitely weak solution. In the sar¬ 
code layer, cells, which are universally recognized as “ calcareous 
glands,” make their appearance in the neighbourhood of rapidly form¬ 
ing calcareous tissue. The sarcode has collected and concentrated a 
quantity of the infinitely weak calcareous solution, and has thrown a 
cell-wall round it to retain it for future use. Again, organic matter 
diffused in the sea is exposed to the absorbent surface of the sarcode 
zooid. The organic matter is assimilated, its elements are recom¬ 
bined, and forthwith a globule of oil is wrapped up in a cell-wall and 
laid aside. This rudimentary gland is not, according to this view, 
made from the sarcode as from a blastema, but it is made by the sar¬ 
code as by an active vital agent. 
I by no means imagine that these processes are performed by any 
hitherto undetected form of organization. I am inclined to believe, 
on the contrary, that every particle of sarcode entering into the 
composition of any organized being, whether it exist in mass or dif¬ 
fused among special tissues and organs, is potentially the whole 
being, and may, under favourable circumstances, reproduce an organ¬ 
ism, a repetition of the organism from which it was detached; 
(whether as the essential element of a bud, of an ovum, or of a 
spermatozoon). 
I intend entering more fully into this subject in a future part of 
this paper. I merely mention these points at present in order to ex¬ 
plain fully the kind of vital activity which I think I am entitled to 
claim for the sarcode element. 
