LINDLEYS VEGETABLE KINGDOM. 
309 
being old acquaintances. They are for the 
most part very accurately and finely executed, 
and give a perfect insight into all the com- 
plicated organization of the apparently most 
trivial, but, thus illustrated, they become most 
important, subjects, for their diminutiveness 
renders their structure the more wonderful. 
The Vegetable Kingdom opens with the 
very lowest order of plants ; but it is preceded 
by a discussion upon the subject of the par- 
ticular line at which the Animal Kingdom ends 
and the Vegetable begins ; and we are tempted 
to quote a portion of it, as it takes some views 
not quite so common-place as those of many 
other authors ; and the conclusion which is 
drawn comes home to the reader. 
" When the Animal Kingdom is studied as 
a vast whole, and not merely in the highly- 
developed classes of Mammals, Birds, and 
Reptiles, the naturalist perceives forms with 
which he is most familiar gradually changing, 
organs which are indispensable to the highest 
orders of Animals disappearing, the limbs 
ceasing to be formed, all the internal structure 
of the body simplified, and, at last, nothing 
left but pulpy and seemingly shapeless masses, 
such as inhabit shells. Let his power of vision 
be enlarged, and the microscope discovers to 
his amazement, that the Animal Kingdom has 
not ceased with the soft-bodied creatures at 
which his inquiry had stopped, but that a new 
and vast field of observation opens before 
him, teeming with myriads of forms, which 
are, as it were, the beginning of another king- 
dom of nature. Nevertheless, he soon finds 
that the smallness of the size of these creatures 
is no hindrance to their possessing the peculiar 
attributes of animal life. Though bones, and 
muscles, and external limbs, with veins, 
arteries, and nerves, may have disappeared, 
or become too fine for human vision, yet 
there is still left the animal motion, and the 
power of hunting for prey, of feeding by a 
mouth and by the destruction of other species, 
which is one of the great marks of animal 
structure. He sees that cells, although so small 
that the acutest vision and the most powerful 
instruments are alone sufficient to detect them, 
are the recipients of a stomach, of eyes, of a 
mouth. He perceives in such bodies all those 
elements of activity, by which the Animal 
Kingdom is in general so well distinguished 
from the passive Region of plants. 
"And hence it is that those who deal in 
generals only, without descending to parti- 
culars, pronounce with a voice of authority 
that the Animal and Vegetable Kingdoms are 
sundered by decisive characteristics. The 
zoologist declares that the power of spontaneous 
motion, and the feeding by a stomach, are 
qualities confined to the Animal Kingdom. 
But numerous plants move with all the appear- 
ance of spontaneity ; the spores of those Con- 
ferva; which are sometimes called Zoosporous, 
swim in water with great activity ; the fila- 
ments of Zygnemata combine with the energy 
of animal life ; and as for a stomach, it is 
impossible to say, that the whole interior of 
a living independent cell is not a stomach. 
Chemists once referred to the presence of 
nitrogen as a certain characteristic of animals; 
but plants abound in nitrogen. With more 
reason they now appeal to the existence of 
starch in plants, an organic compound un- 
known among the animal creation. And this 
is perhaps the best mark of distinction that has 
hitherto been found ; for it is universally 
present in plants, and has enabled Mr. Payen 
to confirm by chemical evidence the vegetable 
nature of certain productions till lately re- 
garded as Zoophytes, and therefore as belong- 
ing to the Animal Kingdom. (Ann. Sc. Nat. 
2 iter. xx. 65.) 
" But it has been long ago asserted by Bory 
de St. Vincent, and others, that there exist in 
nature organized bodies which are animal at 
one period of their lives, and vegetable at 
another ! This, if true, would for ever put 
an end to the possibility of distinguishing the 
two kingdoms when they shall each have 
arrived at their lowest forms. Its truth has, 
however, been denied. On the contrary, 
Kiitzing, in his recent magnificent work on 
Alga;, insists that it happens in hisUlothrix zo- 
nata. He asserts that in the cells of that plant 
there are found minute animalcules, with a 
red eye-point, and a transparent mouth-place ; 
that they are not, in fact, distinguishable from 
Ehrenberg's Microglena monadina ; these 
bodies, however, are animals only for a time. 
At last they grow into vegetable threads, the 
lowest joint of which still exhibits the red 
eye-point. This phenomenon, which Kiitzing 
assures us he has ascertained beyond all pos- 
sibility of doubt, puts an end to the question 
of, whether animals and plants can be dis- 
tinguished at the limits of their two kingdoms, 
and sufficiently accounts for the conflicting 
opinions that naturalists entertain as to the 
nature of many of the simpler forms of or- 
ganization. 
" Such being the ease, it is not worth 
attempting to decide, whether the lowest forms 
of structure, to be presently mentioned, belong 
to the one Kingdom or the other. It will be. 
sufficient that they have been regarded as 
plants by many eminent naturalists. 
" It is in this microscopical cellular state of 
existence that the Animal Kingdom ends, and 
the Vegetable commences. It is from this 
point that the naturalist who would learn how 
to classify the Kingdom of Plants must take 
his departure. He perceives that those species 
which consist of cells, either independent of 
