All or some part of that period, when North America and Europe were for the most part covered with glacial ice, intervenes between the time of man's undoubted existence—the time of the Cannstadt, Cro-Magnon, and Furfooz races—and the beginning of the time figured by these savants.
PERSONAL, like national, history has its epochs; brief seasons, during which life is fuller than usual, and the present is more obviously pregnant with the future than at other times. For me, the year 1851 constitutes such an epoch. In November, 1850, I had returned to England after an absence, which not only extended over a considerable period of time, but covered the critical age of transition from adolescence to full manhood. In the course of these four years, largely spent in little-explored regions of the other side of the globe, I had been in the world as well as round it, and stored up varied experiences of things and men. Moreover, I had done some bits of scientific work which, as I was pleasantly surprised to learn on my return, were better thought of than I had, I will not say expected, but ventured to hope, when I sent them home; and they provided me with an introduction to the scientific society of London. I found the new world, into which I thus suddenly dropped, extremely interesting, and its inhabitants kindly disposed toward the intruder. The veterans were civil, the younger men cordial; and it speedily dawned upon my mind that I had found the right place for myself, if I could only contrive to stop in it. As time went on, I acted upon this conviction; and, fortune greatly aiding effort, the end of it was thirty odd years of pretty hard toil, partly as an investigator and teacher in one branch of natural knowledge, and partly as a half-voluntary, half-compelled man-of-all-work for the scientific household in general.
But the year 1851 has other and even stronger claims to be counted an era in my existence. In the course of the twelve months after my return, I made acquaintances which rapidly ripened into friendships, knit with such strong bonds of mutual affection and mutual respect, that neither the ordinary vicissitudes of life, nor those oppositions in theory and practice which will arise among men of mental constitutions diverse in everything but strength of will, nor, indeed, any power short of almighty Death, has been able to sunder them from that time to this. And among those friends who, as the years rolled on,