DR. DUFFIN, ON PROTOPLASM. 263 
without employing the doctrine of irritation. Instead of 
saying that the activity of a living structure is increased by 
an “irritant”? or “ excitant,’ he would say simply that the 
living matter grows faster, because the access of pabulum to 
it is facilitated, in consequence of rupture of the formed ma- 
terial which surrounds it, or by this formed material being 
rendered more permeable to nutrient fluids.* 
The more active the growth of a tissue the smaller is the 
amount of formed material it contains. If we look to the 
cells of the yelk-bag, we find every grade of germinal matter, 
nucleolus, nucleus, protoplasm, varying in consistence at dif- 
ferent depths, but we have no proof that these are surrounded 
by any proper membrane whatever. The protoplasm is held 
together by its own consistence, and the appearance of “ cells’’ 
or separate masses is due to its having travelled outwards, 
or to its tendency to divide and subdivide. 
We will, in conclusion, endeavour in a few words to show 
still more distinctly the difference between the views brought 
forward in this paper and those of Dr. Beale. This observer 
insists ¢ that physical and chemical changes take place in 
“formed material,” but that vital actions occur in the “ ger- 
minal matter’ alone. All that is necessary to his “ cell” is 
—(1) matter that is active and living, or “ germinal matter ;” 
and (2) matter that is formed and has lived, but is now pas- 
sive, ‘formed material.” Neither “ nucleolus,” “ nucleus,” 
“cell-wall,”’ “cell-contents,” are essentials. The “protoplasm”? 
in the Rhizopoda, &c., according to Beale, consists of parti- 
cles of lwing, active, germinal matter, imbedded in inactive 
formed material, which was itself once germinal matter. In 
using the term “ vital action,’ Beale admits the existence of 
a force or power peculiar to living beings. He would refer 
the movements of protoplasm to the vital power of the living 
particles enterimg into its composition. In all forms of ger- 
minal matter, Beale finds particles so minute that they are 
only just visible under a power of 3000 diameters, and he 
believes that living particles exist which are too minute to be 
seen by any power yet made. Beale therefore refers the move- 
ments seen in protoplasm to the living particles themselves, 
and not to a fluid or basic matter in which they are sus- 
pended ; the latter, which usually exists in inappreciable 
quantity, exhibits motion, but its movements are secondary, 
and the impulse is communicated to it from the living par- 
ticles. 
* See a paper in the ‘ Lancet,’ April, 1863. 
+ See papers read before the British Association for the Advancement of 
Science, 1861 and 1862; also ‘ Archives of Medicine,’ vols. ii and iii. 
