Fattori ecologici ed accrescimenjtio in colonie di eudendrium racemosum (gmelin)

Abstract

Colonics of E. raccmosum which were cultivated in thermostatic shelves at 18°C, fed dayly with Arlcmta larvae and exposed to natural light from the month of October until the middle of April, underwent a seasonal growth cycle which sltowcd a marked increase from February to April. Experiments which were carried on from April to the middle of June by exposing part of the colonics for a number of hours corresponding to the winter daily illumination (h. 8,30) demonstrated that the spring increased growth rate is due to the higher duration of the illumination. A marked difference in grow’th has been observed between colonics which were exposed to illumination of short duration and eonlrols that were exposed to illumination of short duration and controls that were exposed to the entire duration of the daily spring illumination. Growth was much more marked in the latter colonics. © 1964 Taylor & Francis Group, LLC.