Within a skeletal muscle, individual muscle fibers are grouped into bundles called fascicles by which middle connective tissue layer?

1. Inside the epimysium, skeletal muscle fibers are not loose but organized into bundles. 2. Each such bundle is called a fascicle. 3. The middle mysia layer that organizes fibers into fascicles is the perimysium. 4. Epimysium wraps the whole muscle and endomysium wraps single fibers, and sarcolemma is a fiber's own membrane, so none of these organize fibers into fascicles. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 10 "Muscle Tissue", section 10.2, p. 407_