Memoirs of a Revolutionist by Peter Kropotkin

At the same time I worked a great deal for the Russian Geographical Society in my capacity of secretary to its section of physical geography.

Great interest was taken then in the exploration of Turkestan and the Pamírs. Severtzov had just returned after several years of travel. A great zoologist, a gifted geographer, and one of the most intelligent men I ever came across, he, like so many Russians, disliked writing. When he had made an oral communication at a meeting of the society, he could not be induced to write anything beyond revising the reports of his communication, so that all that has been published over his signature is very far from doing full justice to the real value of the observations and the generalizations he had made. This reluctance to put down in writing the results of thought and observation is unfortunately not uncommon in Russia. The remarks on the orography of Turkestan, on the geographical distribution of plants and animals, on the part played by hybrids in the production of new species of birds, and so on, which I have heard Severtzov make, and the observations on the importance of mutual support in the progressive development of species which I have found just mentioned in a couple of lines in some report of a meeting -- these bore the stamp of more than ordinary talent and originality; but he did not possess the exuberant force of exposition in an appropriately beautiful form which might have made of him one of the most prominent men of science of our time.