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this rhythmical contraction and dilatation, the ‘ systole ’ and 
‘ diastole/ terms employed in connection with the movements 
of the last-named organ in the higher animals. 
“ Thus you will see that Amoeba wliich is at present regarded 
as the lowest type of animals, is in fact a mass of cell- contents, 
or ‘ sarcode/ without a definite cell- wall, possessing the power 
of locomotion, and the capability of nourishing itself. How it 
reproduces itself; and whether it really is a perfectly formed 
animalcule, or only the early stage of one, is not definitely 
ascertained. 
“The other living type, Actinophrys (pi. viii., fig. 2), differs 
from Amoeba chiefly in its members of locomotion being con- 
stant, and in the structure of the body being reticulated after 
the manner of a honeycomb, and not gelatinous ; indeed, it 
resembles the section of a minute twig of the pine. 
“ Its locomotive members (pseudopodia) are believed to have 
the power to paralyze its prey, which you will be surprised to 
hear often consists of highly organized animalcules.* These it 
engulfs in the same manner as Amoeba, digesting the nutri- 
tive portion, and ejecting what is indigestible. 
“ Let me just relate one more circumstance concerning Actino- 
phrys, and then we must pass on to the bell-flower animalcule. 
“ When two of these forms come into contact with one another 
it is not at all uncommon for them to coalesce so completely as 
to form one perfect animalcule ; and the new creature possesses 
precisely the same properties as the two of which it is composed. 
“ I mention this circumstance, in order to show you how 
remarkably simple must be the structure of the * lowest forms 
of life/ when two of them can amalgamate, and yet retain their 
vital properties unimpaired. 
“ In concluding my remarks concerning them, I would observe 
that they have been placed by systematic zoologists in a group 
of animalcules, called ‘ Rhizopoda/ or ‘ root-footed/ from the 
peculiar shape of them members of locomotion. f 
* Amoeba, I believe, feeds on the simplest kinds of plants. 
(PI. viii., fig. 2, represents Actinophrys Sol , as I have myself seen it, 
seizing and digesting a Stentor, or trumpet animalcule.) In Actinophrys the 
contractile vesicle is clearly visible, and after a meal its contractions and 
dilatations are very regular and perceptible. (Fig. 2 a.) 
t Mr. J. R. Greene (whose excellent little work, “ A Manual of the Sub- 
Kingdom Protozoa,” is strongly recommended to the student of this branch 
of natural history) aptly describes Amoeba ; and the extraordinary phenomena 
which accompany the life of this lowliest of living forms warrant me in 
making an extract — even at the risk of a little repetition : — 
“ When first placed under the microscope, the Amoeba presents the appear- 
ance of a globular mass of a semi-transparent jelly, destitute of any apparent 
organization. This seemingly helpless being soon, however, commences to show 
signs of life, by pushing out in various directions portions of the jelly-like 
substance of which it is composed. By expanding one of these prolongations, 
