THE COMPARATIVE DISTRIBUTION OF TWO CHROMATOPHOROTROPIC HORMONES (CDH AND CBLH) IN CRUSTACEAN NERVOUS SYSTEMS

Abstract

The parts of the C. N. S. of a number of spp. of crustaceans representing the Isopoda, Natanlia, Astacura, Anomura, and Brachyura were extracted and assayed upon eyestalkless specimens of Crago to dctn. the distr. of 2 chromatophoro-tropic principles. One of these, the Crago-tail-darkening principle. (CDH) was largely restricted to the tritocerebral commissure of the natantian, Crago, was found in significant amts. throughout the C. N. S. of the natantian, Palaemonetes, the astacurans, and the isopod, Idothea, was principally in the posterior thoracic cord region of the anomuran, Pagurus, and was entirely absent in the five genera of brachyurans examined. The second principle, Crago-body-lightening (CBLH) was found in all parts of the N. S. tested but appeared least in quantity in the abdominal cords of Palaemonetes, Homarus, and Cambarus where its presence was almost entirely obscured by the concurrently present CDH, which in these regions apparently due to the absence of the antagonistic CBLH, was able simultaneously to darken both body and tail.