01427nas a2200121   4500008004100000245011000041210006900151300001000220490000800230520099900238100001601237856005201253       1982                        eng d00aUltrastructure of copulatory organs in Turbellaria: 1. Macrostomum sp. and Microstomum sp. (Macrostomida)0 aUltrastructure of copulatory organs in Turbellaria 1 Macrostomum  a39-600 v1013 aThe copulatory organs in Macrostomum sp. and Microstomum sp. contain simple tubular stylets which are intracellular specializations. The stylet in Macrostomum sp. is produced in a syncytium covering part of the prostatic vesicle. The proximal region of the stylet surrounds the vesicle which contains 6 prostatic gland ducts and 6 accessory (sensory) cells containing ciliary rootlets. The stylet in Microstomum sp. is produced in an extension of a syncytium which lines the combined seminal-prostatic vesicle. The stylet is connected to the combined vesicle by a narrow bridge of matrix syncytium through which sperm, prostatic gland products and sensory cilia pass from the vesicle to the stylet lumen. In both species the matrix syncytium can be interpreted as a specialized terminal end of the male canal epithelium. Stylets of Turbellaria and other lower Metazoa are discussed in regards to structure (1 or several pieces) and location (in separate cells, in a syncytium or extracellular).1 aDoe, D., A.  uhttps://macrostomorpha.myspecies.info/node/4694