2. STRANGE MANKINDSThough all the worlds which we entered in the first phase of our adventure were in the throes of the crisis known so well in our own world, some were occupied by races biologically similar to man, others by very different types. The more obviously human races inhabited planets of much the same size and nature as the Earth and the Other Earth. All, whatever the vagaries of their biological history, had finally been moulded by circumstance to the erect form which is evidently most suited to such worlds. Nearly always the two nether limbs were used for locomotion, the two upper limbs for manipulation. Generally there was some sort of head, containing the brain and the organs of remote perception, and perhaps the orifices for eating and breathing. In size these quasi-human t
