establish new species."

To this Professor Kolliker appears to attach some weight. He makes the
suggestion that the short-faced tumbler pigeon may be a pathological
product.

"2. No transitional forms of animals are met with among the organic
remains of earlier epochs."

Upon this, Professor Kolliker remarks that the absence of transitional
forms in the fossil world, though not necessarily fatal to Darwin's
views, weakens his case.

"3. The struggle for existence does not take place."

To this objection, urged by Pelzeln, Kolliker, very justly, attaches no
weight.

"4. A tendency of organisms to give rise to useful varieties, and a
natural selection, do not exist.

"The varieties which are found arise in consequence of manifold
external influences, and it is not obvious why they all, or partially,
should be particularly useful. Each animal suffices for its own ends,
is perfect of its kind, and needs no further development. Should,
however, a variety be useful and even maintain itself, there is no
obvious reason why it should change any further. The whole conception
of the imperfection of organisms and the necessity of their becoming
perfected is plainly the weakest side of Darwin's Theory, and a 'pis
aller' (Nothbehelf) because Darwin could think of no other principle by