10 
POPULAR SCIENCE REVIEW. 
Selection undoubtedly expresses a great truth, that a struggle 
for existence is always going on among the far too numerous 
offspring of the same parents ; and that, where no other causes 
come into operation, those of the offspring which possess any 
advantageous differences from the remainder will survive to 
the prejudice of the rest, and will have a tendency to perpe- 
tuate this divergence. When, however, Natural Selection is 
brought forward as adequate to account for the whole history 
of biological evolution, it presupposes the principle that no 
change can take place in the way of the evolution of one 
species from another that is not directly and immediately to 
the benefit of that individual species ; — in other words, that 
each form of life exists for its own advantage only. But do we 
not see around us many facts which appear to negative this 
hypothesis? Biological forms have been evolved presenting 
pecidiarities of structure, special developments of particular 
organs, not possessed by their parents, but which, as far as we 
have any means of judging, are and can be of no special advan- 
tage to them in the struggle for life. We seem, indeed, more 
and more compelled to the conclusion that we know next to 
nothing of the laws which govern the evolution of species, and 
the development of the marvellously diverse forms of animal 
and vegetable life that surround us. I cannot myself get away 
from the conclusion that we must attribute the tendency to 
variation which is admitted to be the material on which Natural 
Selection works, to some inherent force belonging of necessity 
to the functions of life, whether animal or vegetable, which is 
independent of, and in some sense superior to, the forces that 
govern the inorganic world. Above all, we are compelled to 
recur to the pre-Darwinian doctrine of Design ; and to believe 
that Nature has some general purpose in the different modes 
in which life is manifested, a purpose not in all cases for the 
immediate advantage of the individual species, but in further- 
ance of some design of general harmony which it may take 
centuries of unwearied observation and laborious toil before we 
discover the key by which we may be able to unlock it. 
EXPLANATION OF PLATE LXXIX. 
Fig. 1. Stapelia sp. (Asclepiadacese). 
„ 2. Bhipsalis funalis (Cactacese). 
„ 3. Euphorbia Tirucalli (Euphorbiacege). 
„ 4. Fruit of Securidaca lanceolata (Polygalacese). 
„ 5. „ „ Seguiera floribunda (Phytolaccaceae). 
„ 6.' ,, „ Gallesia gorazema (Phytolaccacese). 
„ 7. „ „ Heteropterys argyrophsea (Malpighiacese). 
