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The mandibular glands of Blaberus craniifer are examined by histochemical, electrophoretic, thin-layer chromatography and electron microscopical techniques. These glands are known to secrete a volatile aggregative pheromone. The gregarious behaviour increases during insect development and is maximal in imagos. Each gland is composed of a bundle of secretory cells with efferent ductules which arise in a common duct. Secretory cells contain a myeloid secretion more abundant in imagos than in larval stages. Histochemical and electrophoretic criteria show that the myeloid product is made up of a mixture of glycoproteins. A lipidic component is also present in the secretion; its ultrastructural localization remains to be elucidated. Cytological features are in agreement with the gregarious behaviour of cockroaches. Detailed structure and functional interpretation are also discussed.

Temperature increasing in water is responsible in Tench of on activity decrease in neurosecretory cells of preoptic nucleus, and of an increase in sodium plasmatic concentration. Influence of parameter is discussed.

The paracommissural plates of Diplopods are neurohemal "organs" anatomically not individualized in bodies separate from the brain. They lie near the transverse commissure (tritocerebral commissure s.l.). They are composed of at least two distinct types of axon terminals, glial cells, tracheae and a neural lamella facing a blood sinus. The axons of paracommissural plates of originate in neurosecretory cells lying in the ganglions of the transverse commissure. The release of granules partly occurs by exocytosis.

In the African locust after axotomy of the A1 and A2 median protocerebral neurosecretory cells (M-NSC), the decrease of the basophil neurosecretory products into the pericaryons does not result from an increase of the granulolysis but results from an inhibition of the production. The A1 and A2 neurosecretory products, stored anteriorly and posteriorly to the site of the axonal section, seem destroyed by: 1. a suspected entrance of lytic enzymes into the granule (individual granulolysis); 2. a vacuolar inclusion of small or big cytoplasmic areas rich in granules (partial or total collective granulolysis). The axons of the M-NSC, regenerated without reconnexion to the corpora cardiaca (CC), are not separated by glial elements. This glial deficiency could be at the origin of the inhibition of the neurosecretory dynamics observed in the A1 and A2 M-NSC after axotomy and regeneration without reconnexion to the CC.

The number of ergastoplasmic granules in the glandular lobe of the corpora cardiaca is counted in Locusta migratoria migratorioides R. and F. and Schistocerca gregaria Forsk., male adults of different ages, grouped or isolated, having flown or not, and reared in various conditions of hygrometry and temperature. A good correlation was found between the number of ergastoplasmic granules and the utilization of the adipokinetic hormone. Ergastoplasmic granules may représent an original mechanism of hormonal storage used in view of heavy metabolic requirements.

In this paper we analyse the consequences of cutting off axonal track connecting the neurohemal organ (sinus gland) to the pericarya of the protocerebron median part (cortical zones I' and V' - Fig. 1). After cutting the optic lobe, at the medulla interna level (cortex IV' - Fig. 1) a functional neo-sinus gland with 3 types of endings and glial cells is form again. We experimentally investigate the limits of the regeneration area of the sinus gland. Investigation of atypical but functional sinus gland (Fig. 4) allowed us, on one hand, to specify these limits and on the other hand to relate the endings of type III to a cellular type missing in the protocerebron central part. The dynamic study of the setting up of a neo-sinus gland is a quick phenomenon: exocytosis can be seen 24 to 48 h after cutting the optic lobe (Fig. 7). The optic lobe cutting off induces ephemeral modifications, on the one hand, at the level of the beta 1, neurosecretory cells: decrease of golgi activities, crinophagy, presence of crystalline-like structures; on the other hand, at the level of the nearby glial cells which show a lot of dense bodies (Fig. 9, 12).

The ultrastructure of the corpora allata of the last larvar instar of Choleva angustata Fab. was studied. In normal development a complex pattern of changes in the ultrastructure of the corpora allata occurs in relation to the larval age in the active and inactive stages. Towards the end of the active stage, a drastic change occurs, involving an increase in number and volume of vacuoles which fill up the cells. During the fasting stage (in the nymphal clay case) the smooth endoplasmic reticulum disappears while the rough endoplasmic reticulum forms long and sinuous cisternae. Towards the end of the instar, numerous vacuoles appear.

Fasting experiments show striking changes at the ultrastructural level in the corpora allata of the last larval instar of Choleva angustata Fab: increase of the glandular volume and development of the smooth reticulum. These findings suggest that fasting leads to a continuous activity of the corpora allata.

Five types secretory granules are distinguished in the sinus gland of Palaemon serratus on the basis of differences in their diameter and their electron density. Variations in the density of the acoplasm and of the granules are observed for three of these granule types.