1885.] The Relations of Mind and Matter. 683 
cell, are now known to be heterogeneous in structure, composed 
of at least two distinct substances, one of which exists as very 
minute fibrils, of which the other occupies the interspaces. This 
organization, very well marked in the cells of the higher animals, 
becomes much less so in the Protozoa, and is only clearly distin- 
guishable in their higher representatives. Yet this is probably 
due to the imperfection of instruments and methods. The ner- 
vous structure has been only recently discovered in the Medusz, 
and has not yet been traced in the stem of the compound Ccelen- 
terates, though this conveys sensory impulses, and doubtless con- 
tains communicating fibrilla. In like manner the fibrillar struc- 
ture may exist in all cells, though not always sufficiently defined 
to be discoverable. 
Again the cilia, so common in the single-celled life forms and 
in many of the surface cells of higher animals, have been traced 
in some instances into direct connection with the fibrillz. Per- 
haps in all cases they are external continuations of the fibrillz, 
and may thus function as the primitive nerve-ending, the sensory 
termination which receives impressions of external motor energy 
and transmits it to the fibrillz to be distributed throughout the sub- 
stance of the cell. There is thus some reason to believe that the 
developed motor apparatus of the highest animal has its primitive 
counterpart in every cell, and that the unfolded nervous and mus- 
cular organism of man is but a direct development of that existing 
in the Infusoria. In Amoeba the pseudopod may function as a sen- 
sory organ and receive motor impressions which are distributed 
throughout the celi mass. Tissue contraction seems to be the 
general result of such motor influence, however received and dis- 
tributed. ý 
Fg N yeh OB: 
T ate eh Lamy eas Pi, Rg | 
motor apparatus. It has been clearly shown that fine threads of 3 
protoplasm connect contiguous cells in frequent instances, 
servers have seen this structure in the cells of numerous species 
of plants, and some writers look upon it as universal in plant 
cells. In addition to the protoplasmic threads which join the 
nucleus to the cell wall, others pass through the wall, probably 
through minute apertures, and connect with the protoplasm of ` 
one or more neighboring cells. Possibly this, may be a result of 
cell division. When pir cell separates into two its protoplasm 
may not completely separate. And it is quite conceivable that 
