21 
function and further, the diffused contractility of living animal plasm might 
be considered distinctive if we could attach to it the faculty of spontaneity. 
But it may fairly be doubted whether the assimilation of food or the exercise 
of motility is in any sense more spontaneous in a monad than in a particle 
of vegetable plasm. For my own part, I reject all belief in the spontaneity 
of action as related to consciousness and will in all animals destitute of cerebral 
ganglia. For the will of the creature, 1 substitute that of the Creator, 
manifested by the conditions and laws of creation, by virtue of which animal 
life exists ; thus 1 place the source of all actions of the lower animals in that 
organic necessity which is not of the animal's choice. Irrespective of 
volitional movement, there can be no dispute as to contraction of proto- 
plasm under the influence of external irritants; the retraction of pseudopodia 
when coming suddenly in contact with foreign particles may however be 
motility without sensation or conscious perception. I compare it with what is 
called reflex action, in animals where this is distinctly referable to nerve 
organization of a peculiar kind; but all that we know of terminal nerve 
matter, leads to the inference that it is a formless soft albuminous plasm, 
possessing a peculiar molecular constitution. The formed ganglion or nerve 
is not sensitive or motory in property merely because it is thus organised, 
but because, its contained softer substance has an endowment associated 
with its ultimate constitution rather than that which we call structural 
differentiation into "organs.'' 
The vital action or vital force of living organic matter, whether animal or 
vegetable, when reduced to its most elementary form, may be summed up in 
the words — self-preservation, growth, reproduction. Assimilation of matter 
and reproduction are equally the phenomena of vegetable and animal life, and 
morphologically the modes of reproduction are exactly parallelled in both cases. 
The process of fissure, of encystation, of development of zoospores, &c, are 
essentially the same in cryptogamous plants, and in cryptogatnous 
animals, and there is no a priori ground for expecting differences of organic 
instrumentation where there is no difference of function. 
To return from this digression. My original intention in this paper was 
to place before you the widely varying life -histories of the Monad and the 
Amoeba, and for this purpose to have given, in addition to the foregoing 
account of new Amoebae forms, an abstract of Cienkowski's careful observa- 
tions of certain Monadinse. I hope to supply what is now omitted, and to 
discuss some questions of great interest in connection with these lowest 
forms of organic life— their possible origin and conditions of existence. But 
1 must here content myself with repeating the opinions before expressed, 
that ama.boid phenomena are too universal to be considered distinguishing 
