Observations on a proprioceptive system in the legs of the scorpion hadrurus hirsutus

Abstract

1. 1. The ambulatory legs of Hadrurus hirsutus provide excellent experimental material for the study of proprioceptors. 2. 2. Within the proximal segments of the leg, the coxa, trochanter and femur there are one main leg nerve and two small leg nerves. One of these lies against the dorsal aspect and one against the ventral aspect of the leg in the femur. Each ends at a small proprioceptor, the dorsal small leg nerve continuing into the patella and innervating another site at the patella-tibial joint. 3. 3. Details are given of the physiological properties of some of these units in terms of sensitivity to extensions and flexions. 4. 4. Some indication is also given of the sensory responses of cuticular hairs that extend from the cuticle surface. 5. 5. Electron micrographs reveal a limited number of axons in the dorsal small leg nerve. Short morphological descriptions are given of the major features seen in the structure of the nervous system.