HEMOGLOBIN AND OXYGEN: AFFINITIES IN SEVEN SPECIES OF SCIURIDAE.

Studies of the respiratory function of the bloods of seven species of squirrels suggest that, in the evolution and adaptive radiation of this group, the oxygen affinity of hemoglobin has changed in a manner to better adapt the various species to different ways of life and different habitats. These changes are shown by the relative positions of the oxygen-dissociation curves of bloods of several species having dissimilar habits and environments.