850shift of a certain amount of water from the intracellular to the extracellular space. However the results obtained do not indicate whether the increase of inulin uptake due to contractile activity can be attributed to an actual change of volume of the extracellular space rather than to a modification in the diffusion kinetics of inulin: in this latter case we must assume that non equilibrium conditions are present H. During contractions, inulin might be taken up more easily by compartments (perhaps other than the extracellular space) where, Experientia 37 (1981), Birkh/iuser Verlag, Basel (Schweiz) in resting conditions, it enters at a very low rate: it seems difficult to explain why the phenomenon should be less pronounced or absent following isotonic contractions. In order to clarify the results obtained, a further investigation will be devoted to the diffusion kinetics of inulin and HTO in resting and active muscles. Anyhow the results obtained suggest that the determination of cellular electrolytes in isolated muscle preparations should be accompanied by an accurate measurement of the extracellular space and its possible changes due to the experimental conditions. Summary. A peculiar neurosecretory system is reported in 6 teleost species; Clarias batrachus, Heteropneustes fossilis, Mystus seenghala, Ompak pabda, Glassogobius giuris and Notopterus notopterus. It is located in the gill region close to the pseudobranch or to the carotid labyrinth. The neurosecretory ceils have been identified using stains specific for neurosecretion. The results are discussed in the light of the association of the neurosecretory system with the pseudobranch or the carotid labyrinth, and the airbreathing habit of these fishes.In fishes, only 2 neurosecretory systems are known; the hypophysial system of the head and the caudal neurosecretory system of the tail. A peculiar 3rd system of neurosecretion has been found by us to exist in certain fishes, and in the present report an account of this is presented. The neurosecretory cells have been identified histologically, using neurosecretory stains like aldehyde fuchsin 2, acidviolet 3 and iron-haematoxylin 4. So far, this system has been found in 6 teleostean species; namely Clarias batrachus, Heteropneustes fossilis, Mystus seenghala, Ompak pabda, Glassogobius giuris and Notopterus notopterus, which belong to 3 different orders, but not in the carps Labeo rohita and Cirrhinus mrigala. Results. In the 6 species mentioned above, neurosecretory cells are found to occur clumped into groups forming a large ganglionic mass, which is located in the gill region in

The C-banding patterns of 6 species of japanese vespertilionine bats are presented. The variation in amount

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The structure and location of "ordinary" lateral-line organs of the fry and the adult specimens of three teleosts, Cirrhina mrigala, Ophicephalus ( C h a n n a ) punctatus and Gobius striatus, have been studied and the results have been discussed. The stalked condition of surface organs, described for G. striatus, i s a new feature reported for the first time in this communication. An attempt has been made to classify "ordinary" lateral-line organs on morphological grounds, especially the group of "pit organs," taking into consideration the orientation of the neuromast concerned in relation to the surface of the adjacent skin, the basement membrane, the dermis and the thickness of the surrounding epidermis.

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The development of the electric organs of Gymnarchus niloticus has been studied and the origin and histogenesis of a n electroplate worked out. A segmental origin of the electroplate is reported for the first time for this fish. Light has been thrown on many hitherto obscure phenomena, viz., growth of core girth, loss of transverse striations on the myofibrillar elements, differentiation of electroplate polarities, shortening in length of the electroplate etc. The transverse striations of the myofibrillar bundle of the electroplate primordium progressively disappear with development owing to splitting apart of the constituent myofilaments and consequent loss of their parallel order, and not to degeneration of the myofibrillar bundle. The excessive growth of the core girth of the electroplates is caused by the deposition of some kind of interfibrillar substance probably secreted by the peripheral cytoplasm.

The development of neuromasts was studied in two species of teleosts, CiTThinU mrigala Ham. Buch. and Ophicephalus punctatus Bloch, and the findings are presented and discussed. It has been discovered, in the course of this investigation, that a neuromast arises by a process of invagination -a fact hitherto not reported.The occurrence of the dorsal lateral line and the accessory lateral line of the trunk, in addition to the main lateral line, has also been reported for the first time for teleosts, although known for other bony fishes.

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