Date of Award

Summer 1993

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Robert K. Rose

Committee Member

Ralph Stevens

Committee Member

Keith A. Carson

Call Number for Print

Special Collections LD4331.B46 W55


The perinea! gland in the hispid cotton rat, Sigmodon hispidus, is a seasonally cyclic, subcutaneously located organ which is associated with the reproductive system. On gross dissection, the gland possesses a strong attachment to the penis with only loose fascia! connections to the rectum and surrounding muscle and skin. Histologic exam confirms this connection to the reproductive tract and shows the organ to be a compound tubuloacinar gland with a projection leading into the penis. The cyclic hypertrophy and regression of the gland closely parallels that of the testes and seminal vesicles indicating that this cyclicity may be under androgen control. The weight of the gland also shows extremely high correlation to the weights of these other reproductive organs (Pearson's Correlation Coefficient to testes weight = 0.933 and to seminal vesicle weight = 0.930; P < 0.0001). Field testing to determine the function of the glandular product and its effect on wild populations initially indicated an attractant effect on males within the area when trapping was done near the end of the breeding season. An additional test was performed in an attempt to determine the chemical nature of the active component of the glandular secretion. Chemical extraction of the glandular product was done and field testing was established to determine the effects of the different fractions on wild populations. The results of this test proved inconclusive indicating a need for additional studies into the function of the gland.


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