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Strictly speaking, Darwin did not write about a direction to evolution (better and better, for instance) but spoke only of change."
From Darwin himself:
It may be said that natural selection is daily and hourly scrutinising, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.
http://www.talkorigins.org/faqs/origin/chapter4.html
Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
http://www.talkorigins.org/faqs/origin/chapter14.html
You may want to read Darwin before you presume to quote him.
Darwin was clearly talking about natural selection leading to a form adapted to the conditions that the creature found itself in. The creature continues to perfect its functions and form to meet the local conditions. The underlined portion of your first quote supports that interpretation.
The last part of the second paragraph you quote expresses his wonder at the beauty of the amazing variety. No surprise, we are capable of wonder. The first part says that in Darwin's view natural selection leads to complexity, and he tags the more complex animals as "higher animals". He could just as easily said "more complex animals".
My earlier comment was making the point that Darwin did not see "improvement" from a strictly anthropocentric view- his concept of "better" was a form more adapted to its local conditions. Many read Darwin from a human viewpoint, that "more evolved" means more perfect from our point of view and not from the viewpoint of the process. Thus, the concept that we humans are "more evolved" than some other species and therefore "better" than that other.
So a complex creature gradually changing to a less complex one to meet the demands of its environment is, to Darwin, improvement and advancement. To many people I have spoken with, this Darwinian betterment is seen as degradation, downward evolution, or devolution.
He did not see evolution as necessarily leading to a crown of creation, an endpoint of perfection, some evolutionary goal, but change to adapt.
http://www.gutenberg.org/etext/2009