No abstract

Two histophysical methods (electron microprobe and ion microanalyzer) were used on sections of Annelids in order to study the inorganic composition of cement secretory glands. Mg, Ca and P were demonstrated in large amounts in the secretions, associated with organic matter. Traces, or no, Fe, Al and Si were found. Possibilities of artifacts are discussed, and these results are compared with biochemical methods. A hypothesis is proposed in order to explain the differences observed between biochemical and present results, which suggest, for the hardening of cements a different chemical mechanism to that suggested by Vovelle in annelid Sabellaria alveolata.

No abstract

The S cells within the tubules of the hepatopancreas in the terrestrial isopod Oniscus asellus show numerous infoldings of the plasma membrane, which are involved in the uptake of hemolymph proteins, and a lysosomal apparatus that ensures the breakdown of the ingested material. The catabolic process leads to an accumulation of wastes in the form of spherocrystals. The most important components of the spherocrystals are uric acid, copper sulfide, which we consider to originate in the breakdown of hemocyanin monomers, alkaline-earth phosphates, which could be produced by enzymatic activities, and zinc. Moreover, in the marine species Ligia oceanica a silver salt (sulfide?) is stored in the spherocrystals. The S cells function as a storage type of excretory system. Their role is similar to urate cells in arthropods, nephrocytes in insects, and pore cells in molluscs. In the latter, the storage of silver is important in marine environments only.