DR. BEALE, ON CONTRACTILITY. 183 
corpuscle, or young epithelial cell; but it is generally considered 
that all these movements depend on a property which has 
long been known as contractility. And yet one would hardly 
conceive it possible that even a casual observer, who had 
attentively watched ciliary or muscular action, and the move- 
ments of an Ameeba, for example, would fail to discern a 
remarkable difference in the movements he observed, although 
he might be quite unable to define in what essential points 
the movements differed. Not only are there essential dif- 
ferences between these (at least) two classes of movements, 
both of which occur in all the higher organisms, but I think 
it can be shown that the matter which is the seat of the 
observed motion is not of the same nature in each case. 
I have endeavoured to prove that the so-called moving matter 
(sarcode) of an Amceba or of a mucus-corpuscle, white blood 
or pus-corpuscle, corresponds to, or is homologous with, the so- 
called “ nucleus,” and not with contractile material of muscle. 
The moving matter of the former and the so-called “nucleus ” 
of the latter correspond, and I have termed this living or 
germinal matter, while the latter I consider to be formed 
matter, and therefore no longer the seat of vital changes. 
In a paper published in the last number of my “ Archives,”’ 
I have adduced facts in favour of the view that masses of 
germinal matter not only alter their form, but move from 
place to place. The movements which affect the germinal 
matter of muscle are of a nature essentially different from 
the contraction of the muscular tissue; but the movements 
observed in all kinds of germinal matter are, I believe, the 
same in their essential nature. Thus the movements in the 
Tradescantia, and many vegetable cells, the movements of 
the pseudopodia of the Foraminifera, those of the Ameeba, 
&e., are undoubtedly of the same nature as those which 
occur in the mucus- and pus-corpuscles, young epithelial 
cells, germinal matter of the ‘corpuscles’ of the cornea, and 
every other kind of germinal matter. 
For the sake of discussion it is only necessary to take one 
example of the two classes of movements which have been 
included under the head of Contractility, and I will, there- 
fore, contrast the movements of the mucus-corpuscle and the 
contraction of muscle. 
With regard to the muscle :—When contraction occurs it 
diminishes in length, and increases in width and thickness, 
The matter of which it is composed, for the most part, moves 
alternately in two directions, at right angles to one another. 
Each particle of contractile material retains the same relation 
with respect to neighbouring particles during the relaxed 
