Abstract
The postnatal development of secre-tory function of the eccrine sweat glands in the foot pad of the dog was followed from the newborn stage to about 6 months after birth, in particular reference to the cholinesterase activities associated with these glands. The sweat glands in the puppies of early postnatal days were found to be completely devoid of secretory activity up to 2 weeks or more after birth. Establishment of the sweat gland function was attained in the age of about one month in the majority. The cholinesterase activity in the secretory cells of the sweat glands, which is of pseudo type, was found to be almost neglegible within a few days of age. It started to exhibit slight but definite activity within 1_??_2 weeks and reached its maximum in about 4_??_5 weeks after birth, which roughly corresponded with the age when the secretory activity of the glands was established. In contrast, the nerve fibers surrounding the secretory portion of sweat glands showed the defi-nite specific cholinesterase activity already in the very early newborn stage. The significance of these findings was discussed.
