76 Death and Individuality . [February, 
problem of death is, first, whether growing old ( veraltung , 
involution) is a universal phenomenon of life. Weismann’s 
first article was an address delivered before the German 
Naturforscher versammlung, September, 1881, and subse- 
quently republished at Jena. He advanced then the view 
that for unicellular organisms there is no death except 
through accident ; that the propagation being by simple 
division, we must assume that the process of division may 
go on for ever. He does not even consider whether the 
cells form cycles, and whether these cycles need to be 
renewed; so that he misses the real problem. On the con- 
trary, he is enchained a prisoner to the mystical idea of 
individuality, and reasons as if individuality rendered direCt 
comparisons legitimate between things essentially different. 
All his reasoning is based upon the idea that an individual 
protozoon is comparable to an individual dog, and so on. 
The argument just made against him was to show that the 
basis of his whole fabric is illusory. Biitschli, in his short 
article, called forth by Weismann’s, partially liberates him- 
self from the confusion as to individuality, and propounds 
the hypothesis of a lebensferment, which he supposes to be 
continually resumed in Protozoa, which he thus assumes to 
be potentially immortal. He also fails to recognise that the 
true question is, not whether single Protozoa die, but 
whether they form senescent cycles. In this error he is fol- 
lowed by Cholodowsky, who also admits that natural death 
is restricted to the multicellular animals, but overlooks what 
would be its only possible homologue among Protozoa. 
Goette seems to me to have made a distinct advance 
beyond his predecessors, for he has attempted to show that 
there is a death common to all organisms. Especially is 
his conclusion that death and reproduction are intimately 
connected to be noted as important ; but his thought appears 
to me often vague and obscure, and to many of his views I 
can by no means assent. I have just asserted that death 
and reproduction are intimately connected. Now, if my 
theory is correCt, it is evident that each cycle, before it is 
completely exhausted, must produce the initials of new 
cycles : hence the connection in time between maturity, or 
the approach of death, and sexual reproduction. By specu- 
lation upon the few available faCts I have reached the 
following hypothesis : — Originally each cell of a cycle was 
a distinCt individual ; the exhaustion of the last cells of the 
cycle caused them to become sexual bodies and to conjugate ; 
conjugation renews the power of division in the conjugated 
individuals, and therewith a new cycle is begun. Subse- 
quently multicellular animals were evolved, and in these the 
