[Comparative morphometric data on the epiphysis, the subfornical organ, and the anterior pituitary gland in 2 groups of pure strain Wistar female rats, SPF or conventional].

In SPF female rats, the pineal gland is less voluminous and its cell-nuclei are smaller than those of conventionnal female rats. This confirms (with the voluminous adrenals previously reported) the stressing action of the absence of pathogenic germs on these animals. The anterior lobe of the hypophysis is slightly smaller and subfornical organ a little larger than in conventionnal female rats.