The ship fouling algaEctocarpus

Summary Ultrastructural studies of the asexual plurilocular reproductive stages of the brown algaEctocarpus have been made. The zoospores released from the plurilocular sporangia were found to attach to surfaces by means of an adhesive whose site of formation has been shown to be the Golgi apparatus. A preliminary cytochemical investigation has shown that the adhesive contains polysaccharide. This forms the basis for a more precise chemical characterization of the adhesive material.     

TYROSINASE AND PLANT RESPIRATION

The evidence presented in this paper supports the conclusion that at least 85 per cent of the oxygen uptake of the respiring tissue of potato tuber enters the chemistry of the cell by way of a tyrosinase-catalyzed oxidation. The qualitative aspects of this conclusion are in agreement with the claim made by Boswell and Whiting. However, the evidence offered by them in support of this conclusion is shown to be inadequate.     

A New Vector of Haemoproteus colmubae in England

SUMMARY. Haemoproteus columbae of English wood pigeons ( Columba palumbus palumbus L.) was found to undergo sporogony in Ornithomyia avicularia. It is suggested that this insect is a vector of H. columbae , in spite of the failure of six attempts to transmit the haemosporidian to uninfected domestic pigeons ( C. livia var. domestica ) by the bite, or injection, of infected O. avicularia.