The Growth of the Transverse Sectional Area (TSA) of M. Semitendinosus in the Dog and Horse and its Relation to Athletic Ability in the Two Species

The transverse sectional area (TSA) of m. semitendinosus grows at a greater rate than the 2/3 power of liveweight in both Greyhounds and Thoroughbreds (athletic animals) while it increases at a rate proportional to liveweight in other breeds of dogs and horses (non-athletes). Although the TSA of the muscle in the adult athletes of both species is greater than that of the less fortunate fellow specific members there is no significant difference in the TSA of the muscle between the perinates of the two types of animals within each species. Thoroughbred cross horses have TSA values similar to those of Thoroughbreds.