Fine Structure of the Reproductive System of a Frog Lung Fluke. I. Mehlis' Gland and Associated Ducts

Abstract

As seen with the electron microscope, Mehlis'' gland of the frog lung fluke (Haematoloechus medioplexus) is composed of 3 cell types. Two of the types are secretory and discharge their products, via long processes, into the lumen of the ootype-proximal uterus. Peripheral microtubules are found in the processes, which form desmosomal junctions with epithelial cells of the ootype and proximal uterus. One type of secretory cell produces dense bodies which appear to dissociate after entering the ootype lumen, while the other type, the more abundant of the 2 produces membranous bodies. These bodies appear to become associated (fusion) with vitelline globules and forming eggshells in the lumen of the ootype and proximal uterus. Forming eggshells are generally unstratified and show no evidence of a limiting membrane. The third cell type of Mehlis'' gland is interstitial in distribution and appears to be nonsecretory.