Louis Pastore

Date of Award


Document Type


Degree Name

Master of Science



First Advisor

Francis B. Leftwich


A comparison of the vibratory and epaxial muscles of Crotalus horridus horridus Linnaeus wa smade. muscle fibers, fibrils, filaments, mitochondria and sarcoplasmic reticulum were described in this study. The sarcomeres of the epaxial muscle were almost three times the length of those of the vibratory muscle. The A band was observed to be about twice the length of the I band in the vibratory muscle. As seen in cross section the vibratory muscle had fibrils arranged in discrete packets with a limited number of thick myofilaments. In contrast, the fibrils of epaxial muscle were less conspicuously separated from each other and showed fibrils with about six times as many myofilaments. The vibratory muscle was profusely provided with large spherical mitochondria with highly developed cristae. The epaxial muscle had fewer mitochondria, and these were ellipsoidal and smaller in size with less developed cristae. The saroplasmic reticulum of the vibratory muscle was highly developed with numerous tubules which were continuous between fibrils. A reduced development of reticulum was found in the epaxial muscle. It was concluded of that the vibratory muscle is highly specialized in structures related to an energy production or dissemination of the contraction impulse to the interior of the fiber.

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