106 Notices of Books. [January, 
If, as seems not unlikely, from several faCts detailed in the work 
before us, there is a latent tendency to revolve in the shoots of 
all plants, this very attenuation and elongation will remove what 
was before a hindrance, and the power of twining may thus be 
gradually developed. Those forms which thus became climbers 
would in certain situations enjoy a great advantage over their 
rivals. We find further that the twining faculty appears in plants 
in many different grades. In some it is highly developed, in 
others dormant. There are cases where it appears to have been 
scarcely attained, and others in which it is becoming obsolete. 
From the twiner to the leaf and tendril-climbers the way is paved 
by small gradations. We cannot fail to recognise that the latter 
especially must have nearly the same advantage over twiners 
as these have in turn over plants unable to climb at all. 
We cannot better conclude this brief and necessarily imperfeCt 
survey of a profoundly interesting subjeCt than by quoting a 
portion of the final paragraphs of the work before us : — “When 
we refledt on the wide separation of these (climbing plants) in 
the series, and when we know that in some of the largest well- 
defined orders, such as the Composite, Rubiaceae, Scrophu- 
liariaceae, &c., species in only two or three genera have the 
power of climbing, the conclusion is forced on our minds that 
the capacity for revolving, on which most climbers depend, is 
inherent, though undeveloped in almost every plant in the 
vegetable kingdom. 
It has often been vaguely asserted that plants are distinguished 
from animals by not having the power of movement. It should 
rather be said that plants acquire and display this power only 
when it is of some advantage to them ; this being of compara- 
tively rare occurrence as they are fixed to the ground, and food 
is brought to them by the air and rain.” 
A Course of Practical Instruction in Elementary Biology. By 
T. H. Huxley, LL.D., Sec. R.S., assisted by H. N. 
Martin, D. Sc. London: Macmillan and Co. 
This work is arranged upon a somewhat novel plan. The author 
describes in succession yeast, protococcus, the proteus animal- 
cule, baCteria, moulds, stone-worts, the bracken-fern, the bean- 
plant, the bell-animalcule, the fresh-water polypes, the fresh- 
water mussel, the fresh-water crayfish and the lobster, and, 
lastly, the frog. After the description follows in each case a 
seCtion headed Laboratory Work, and containing instructions for 
the practical examination of the plant or animal in question. By 
way of a specimen of the task thus set the student, we insert an 
abridgment of the “Laboratory Work” on the Amoeba : — 
“ Place a drop of water containing Amcebce on a slide, cover 
with a cover-glass, avoiding pressure, and search over with a 
