The Hardarian gland (an apocrine organ located behind the eye) was removed from one group of muskrats. Another group of muskrats was anesthetized and shampooed. The fur of shampooed and Hardarianectomized muskrats did not appear to repel water as effectively as sham control animals. Both shampooed and Hardarianectomized muskrats had higher rates of heat loss while submerged in a 4 C water bath than sham control animals. The magnitude of heat loss was less for the Hardarianectomized muskrats. Hardarianectomized and shampooed muskrats had elevated rates of evaporative water loss with an estimated cutaneous water loss of 52% and 66% of total evaporative water loss for Hardarianectomized and shampooed muskrats compared with 41 % for control animals. Coating the fur of muskrats with mineral oil tended to retard evaporative water loss. It appears that the Hardarian gland is an effective source of lipids which may be spread onto the fur from the nasal duct by both self and communal grooming. This lipid coat appears to help retard heat loss as well as water flux to and from the skin.
The original publication is available at http://www.jstor.org/stable/30163724