68 
Is Death Universal 2 
[February, 
III. IS DEATH UNIVERSAL? 
t COUPLE of years ago we pointed out (“Journal of 
Science,” 1882, p. 401) the curious faCt that — as 
established by the researches of Btitschli, Weis- 
mann, and Goette — the monocellular Protozoa are not, like 
all higher animals, subject to death. From this faCt we 
drew certain conclusions. The subject has since been fur- 
ther examined by Dr. K. Mobius (“ Biolog. Central-Blatt, 
vol. iv., p. 389). The conclusions of this eminent savant 
may serve at first sight to differ from the views which we 
put forward ; but on closer examination it will, we submit, 
appear that the difference is more verbal than real. Admit- 
ting the same faCts, we apply to them merely somewhat 
different names. 
In monocellular animals which propagate by division the 
entire bodily substance of the older individuals — as Btitschli 
and Weismann have proved — continues to live in the young 
individuals into which the former have resolved themselves 
by the aCt of fission. In the polycellular animals — the 
Metazoa — a part of the body, after passing through the 
various stages of its development, loses the power of carrying 
on vital processes, and dies. Hence Weismann ascribes to 
the Protozoa immortality. He argues that, as they are 
resolved by fission into a number of individuals of which no 
one is older and no one younger, we have an endless series 
of individuals, each of which is as old as the species itself, 
and each of which has the faculty of living on indefinitely 
by constantly renewed fissions. The higher organisms, on 
the other hand (the Metazoa), have lost this faculty of end- 
less life. In them the immortality of the monocellular 
organisms is restricted to the reproduCtion-cells alone. 
The reply of Mobius is substantially that, according to 
the definition hitherto generally accepted, we understand by 
the “immortality” of an individual living being the innate 
attribute, not destructible by external causes, of continuing 
for ever as an individual. 
We must here convict Dr. Mobius of an inaccuracy of 
some importance. Weismann nowhere — as in common with 
ourselves — asserts the immunity of the Protozoa from out- 
ward causes of death. We said expressly that with the 
Protozoa death, “ though common enough, is merely casual, 
