THE DEVELOPMENT OF THE STICHOSOME AND ASSOCIATED STRUCTURES IN TRICHINELLA SPIRALIS

A study has been made on the development of the stichosome in Trichinella spiralis. Stichocytes are seen as cuboidal cells in larvae six days after infection. During the course of development, the stichocytes gradually arrange themselves in two rows above the oesophagus and elongate transversely, tending to dovetail alternately opposite each other. The number of these cells in larvae taken 13 days after infection is only half that observed in the mature larvae. Each stichocyte takes a spiral course as the elongation continues. Superficially this results in an apparent duplication of the number of rectangular cells seen. In fact, the stichosome comprises a row of about 24 to 30 unicellular, binucleate gland cells. Each has two coils and somewhat resembles a spring in form. The intestinal gland cells also originate as two cuboidal cells. These undergo separate development into two gland cells looping around the oesophageal–intestinal junction.