I <S85.’l The Lesson of the Unnucleated Cell . 253 
following hypothesis : — “ Originally each cell of a cycle was 
a distinct individual : the exhaustion of the last cells of a 
cycle cause 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 are evolved, and in these the 
same phenomena occur : but some of the cells have become 
specially organised, and become incapable of assuming the 
sexual state ; hence when the end of the cycle approaches 
only a few cells become sexual, and the animal (or plant) is 
mature. The higher organisms become sexually aftive only 
after having grown for a considerable period, because they 
still preserve the primitive relation. Senility is the auslo- 
scncle reiz of sexual reproduction. 
As the above is the gist of the articles in comment, what 
are the conclusions to be drawn ? that matter in any con- 
crete form is immortal, or that all organisms obey the appa- 
rent presentment of Nature — death, or, in another word, 
mutation. The force of the argument for appears to consist 
in the idea that there are no dead bodies of the Protozoa 
arising from natural causes, and that therefore they must be 
immortal ; against which it might be urged, they being 
microscopic creatures, sufficient experience has not been 
obtained, or that the debris (when death arose from natural 
causes) was resolved in a slight interval into their original 
gaseous composition. The white corpuscles of the blood are 
in continual augmentation, which, giving rise to the red, carry 
on the functions of the organism, and which when exhausted 
are exhaled ; but there are no debris, unless blood-poisoning 
be its synonym.* 
* The literature relating to the corpuscles of the blood is very limited : the 
fullest account of them I find in Huxley’s “Elementary Physiology.” The 
blood corpuscles are so minute that it requires a microscopic power of three 
or four hundred diameters to detect them. Particles are then seen which 
constitute the corpuscles of the blood suspended in the plasma. They are of 
two kinds, the colourless and the red; that the red corpuscle is derived from 
the white “ may be regarded as certain,” the red corpuscle being simply the 
nucleus of the white set free by the bursting of its sac or wall. The colour- 
less or white are the larger, the red the most numerous, and so minute that 
ten millions of them will lie in the space of a square inch; they present the 
appearance of a flattened disc, — soft, flexible, and elastic bodies, — and readily 
squeeze through apertures narrower than the diameters of their own bodies, 
and have no distinct structure. The white differ from them in the extreme 
irregularity of their form and continuing variation of shape. The reproduction 
of the red corpuscles appears to be by spore formation. Of the white, owing 
to the continuous change of shape, the supposition would be that their repro- 
duction was by the process of simple fission. There is no observation to that 
effedt. Haeckel (“ History of Creation,” vol. i., p. 159) gives an example of 
blood corpuscles increasing by self-division, the embryo of a stag. Huxley 
says the origin of the white corpuscle is not determined. “ It is probable that 
