On the spermatophore of ixodid ticks

Structure and formation of the spermatophore and the extrusion of its contents in ixodid ticks were studied. The structure of the ectospermatophore resembles that of argasid ticks, whereas that of the endospermatophore differs completely; it is composed of several organelles which are absent in argasids.The chemical nature of the components of the spermatophore was studied by histochemical methods. The male forms the spermatophore by ejaculating the components in a definite order. The components of the ectospermatophore are deposited one into another—while those of the endospermatophore one on top of the other and are linked together in a chain. The last component to be ejected is a plug that closes the endospermatophore.During extrusion of the endospermatophore all of the components burst out of the ectospermatophore. The endospermatophore sheath evaginates and forms the capsule into which the sperm is inserted. Each capsule has two tube-like appendices.     

Observations on morphology and hydrolytic enzyme histochemistry of excysted metacercariae of Himasthla rhigedana (Trematoda: Echinostomatidae)

The morphology of in vitro excysted metacercariae of Himasthia rhigedana was studied by light microscopy, enzyme histochemistry, and scanning electron microscopy (SEM). The body surface is covered with longitudinal rows of pointed spines which extend from the anterior end to just below the acetabulum. Histochemical methods for acid and alkaline phosphatases, β-glucoronidasc, leucine aminopeplidase, nonspecific esterase, acetylcholinesterase, butyrylcholincsterase, chymotrypsin-like protease, α-galactosidase and β-galactosidase were applied to the excysted metacercariae. Certain systems of the metacercaria containing these enzymes showed positive reactions to the appropriate methods and were selectively visualized. Reactions for alkaline phosphatase occur throughout most of the excretory system while acid phosphatase occurs in the gut, oral, and ventral suckers. Reactions for nonspecific esterases and cholinesterascs are found throughout the nervous system, in the gut, and in the oral and ventral suckers. The results of including specific inhibitors or activators in the incubation medium after preineubation m 10^?5m diethyl p-nitrophenyl phosphate (E-600) suggested that A-and C-typc esterases are present in the gut. Inclusion of 10^?4m eserine in the incubation medium abolished cholinesterase activity in the nervous system.     

Histological and enzyme histochemical changes in the kidney of male bullhead (Cottus gobio) during the spawning period

Histological and enzyme histochemical studies were carried out on the excretory kidney of the male bullhead ( Cottus gobio ). During the spawning season striking morphofunctional changes were observed in the second proximal segment of the kidney tubule. The tubular epithelium was greatly hypertrophied, strongly basophilic and produced a PAS-positive secretion. The enzyme histochemical pattern also changed conspicuously during this time: the alkaline phosphatase activity in the brush border was greatly reduced; the acid phosphatase and non-specific esterase activity in the cytoplasm was distinctly elevated.