PROTOZOA. 63 
vegetable organisms, we will not find it easy to determine, without 
considerable study, which is to become the plant and which the 
animal. It is indeed difficult to trace the precise line of demarcation 
which it is so desirable to establish between these two kingdoms 
of Nature. 
The word zoophyte has been often applied to these lower forms of 
animal life: it is derived from the Greek word (ov, animal, and gurdy, 
plant. To adopt the name zoophyte to indicate a great division of 
the animal kingdom, would, however, lead the reader to imagine that 
there is an ambiguity about the creatures designated, or that they 
belong at once to both kingdoms, or that they might be ranged in- 
differently in the one or the other. But the so-called zoophytes 
are animals, and nothing but animals; and the only justification for 
using a designation which signifies animal-plant is, that many of 
them have, at first sight, an exterior resemblance to plants. 
This likeness between plants and zoophytes was supposed to be 
nowhere more apparent than in the coral. Rooted upon rocks, 
the form of its branches many times subdivided, above all, the 
coloured polyps which at certain stages of their expansion so closely 
resemble the corolla of a flower, gave the coral, it was thought, all the 
form and appearance of a plant. Until the eighteenth century most 
naturalists classed the coral, as Linnzeus once did without the least 
hesitation, in the vegetable world. Réaumur long contended for 
the contrary opinion. The sea anemone was also cited as another 
example of the resemblance borne by certain of the lower animals to 
vegetables. | This resemblance, however, is not seen in the group 
of the lower animals which we prefer to call Protozoa (from «pwr 
the first, and ééy life), and we shall not surprise our readers by 
telling them that the structure of these Protozoa, especially of some 
of the lower forms is excessively simple. We find among them the 
first steps in the scale of animal life, and here a very rudimentary 
organisation was to be expected. In these beings the several parts 
of the body, in place of being disposed symmetrically on each side of 
its longitudinal plane, as occurs in animals of a higher organisation, 
are found to have not as yet become differentiated. The Protozoa we 
need hardly add have neither an articulate skeleton, either exterior 
or interior, nor a nervous system. ‘The organs of the senses, other 
than that perhaps of touch, are altogether absent in the beings which 
belong to this the lowest class of the lowest division of the animal 
kingdom. 7 
Several questions arise here: Has the Protozoon sentiment, 
feeling, preception? Has it consciousness, sense, sensibility? The 
