ANIMALS AND VEGETABLES. 
219 
rently upon good foundation, that there are 
organized forms that are vegetables at one 
period of their existence and animals at 
another. Many of the Conferva?, for ex* 
ample, are equally claimed by Zoologists and 
Botanists : and some among these, as the 
Oscillator ice, are said to be possessed of loco- 
motion in one stage of their growth, while in 
another they are fixed and motionless. So 
nearly, then, do the animal and vegetable 
worlds approximate, remote and separate as 
they appear to be when examined only in their 
typical forms. Light and darkness are distinct 
from each other, and no one possessed of 
eyesight Avould be in danger of confounding 
night with day ; yet he, who looking upon the 
evening sky would attempt to point out 
precisely the line of separation between the 
parting day and the approaching night, would 
have a difficult task to perform. Thus is it 
with the Physiologist who endeavours to draw 
the boundary between these two grand king- 
doms of nature ; for so gradually and imper- 
ceptibly do their confines blend, that it is at 
present utterly out of his power to define 
exactly where vegetable existence ceases and 
animal life begins." — Pp. 5 — H. 
This much appears in the first chapter, and 
the deep interest that pervades every para- 
graph of the work renders it exceedingly 
difficult to select one passage in preference to 
another. If, indeed, we could quote the embel- 
lishments as well as letter-press, which are 
executed in the style that distinguishes nearly 
all the works which Mr. Van Voorst pub- 
lishes, we should have no difficulty about the 
matter ; for it would be no easy task to select 
either an engraving, or the passage referring 
to it, that would not be acceptable. The 
chapter on sponges, the second in the volume, 
gives us the true nature of those extraordinary 
productions ; showing that it is not only all 
life and animation, but refers to the mode of 
increase and the locomotion of the future 
animals ; demonstrating most clearly that a 
substance which has been considered little 
better than a stone in the order of creation, is 
actually a living being, capable, in the earlier 
part of its career, of moving about, though 
fixed at a later period, to grow, and bring 
forth young in large numbers. After this, of 
course, we are prepared for anything. As 
the author concludes his chapter : " With 
these facts before us, relative to the capabili- 
ties of living matter, we are prepared to 
investigate the next forms of creation that 
nature offers to our inspection." We now 
come to the consideration of the third chapter, 
which treats of " Agastric Zoophytes, Fungia?, 
Meandrina?, and the History and Properties of 
the Hydra Viridis ;" the most extraordinary, 
perhaps, of all animalcules. The author, in the 
fourth chapter, gives us his " Classification of 
the various forms of beings composing the 
animal kingdom." — 1. Mammalia. 2. Birds. 
3. Reptiles. 4. Fishes. 5. Insects. G. 
Vermes, or Worms ; thence to the subdivisions 
of each, dispelling as much of the mystery and 
technicality of philosophy as is compatible 
with his subject, and rendering all things plain 
and intelligible. Perhaps the most remark- 
able and least understood wonders of the world 
may be found in the Infusoria, or animalcules 
in water, perfectly invisible to the naked eye, 
but of inconceivably beautiful structure, so 
perfect as to lead us to doubt our own senses 
when the reality is before us. Here we must 
allow the Professor to speak for himself : — 
" Some Infusoria nearly allied to the 
Pr'otens, and furnished with bodies equally 
contractile, are able, notwithstanding the 
mutability of their shape, to construct for 
themselves shelly defences beneath which they 
can retire for shelter or protection. In the 
Arcella, for example, you find an Amoeba, for 
such it is essentially, covered over with a 
shell, resembling that of a limpet ; and truly 
there are some physiologists fanciful enough 
to imagine that we have here, in rudiment, the 
sketching out of what in higher animals will 
show itself under more perfect forms ; so that 
the shell-fish and the tortoise are here typified 
amongst these humblest animals. How that 
may be, we will not pause to ask ; it is suf- 
ficient for our present purpose to learn, that, 
minute as these Infusoria are, they are, many 
of them, able to construct for themselves shells 
of extreme beauty and elaborate workman- 
ship, which, under a good microscope, will 
bear comparison with the most exquisitely 
sculptured that are to be found in the cabinets 
of the conchologist, 
" It is not, however, from their minuteness 
or their beautiful sculpture that these micro- 
scopic shells principally merit our notice : 
small and invisible as they are individually, it 
is perfectly possible that, in the lapse of ages, 
even these exuviae of animals, of whose very 
existence man would for ever have remained 
ignorant but for his glasses, may, by their 
accumulation, absolutely change the geolo- 
gical features of whole regions of this world, 
and give rise to the existence of strata of soil, 
of no trivial interest or importance. We have 
before us a quantity of earth, brought from 
the shores of Lake Lettnaggsjon, near Urnea, 
in Sweden ; an earth which the inhabitants of 
that country have, from time immemorial, 
regarded as being nutritious, and from this 
circumstance, as well as from its whiteness 
and excessive fineness, it has received from 
them the name of Bergmelil, or mountain 
meal. Mixed up with flower this substance 
is even used for bread ; and was formerly 
