A note on the contribution of hepatopancreas to the development of oocytes in the scorpion (Palamnaeus bengalensis)

Zusammenfassung Das Hepatopankreas des Skorpions,Palamnaeus bengalensis, wurde untersucht, um herauszufinden, ob es Rohmaterial für die Entwicklung und Dotterbildung der Oozyten liefert. Es wird gezeigt, dass eine grosse Menge von Ferritin in der Leber gelagert und ausserdem in der sich entwickelnden Oozyte gefunden wird. Das Ferritin in den Oozyten ist auch direkt proportional zu ihrem Wachstum. Das Hepatopankreas scheint auch etwas Melaninkörner und Melaninvorstufen zur Entwicklung der in den Oozyten vorhandenen Melaninvorstufen zu liefern. Melaninvorstufen zusammen mit Sulfhydrylverbindungen bedingen eine gelbe Farbe der reifen Oozyten.     

Possible significance of aminotransferases in tissues of the aestivating fresh water mussel,Lamellidens marginalis (Lamarck)

Summary Both aspartate and alanine aminotransferase levels increased in digestive gland, foot and mantle on aestivation. The free amino acids and pyruvic acid also increased in all tissues. The significance of these changes is discussed in relation to gluconeogenesis.Acknowledgment. The authors thank Professor K.S. Swami, Head, Department of Zoology, for encouragement and Mr I. Kabeer Ahamed for his help.     

Studies on some enzymes of the toad (Bufo melanostictus) testis and their probable role at the time of fertilization

Summary Glycosidases like sialidase,-galactosidase, -L-fucosidase, N-acetyl hexosaminidase and proteases were detected in toad testis. Neuraminic acid aldolase activity was also detected. The enzyme activities were found to vary as production of spermatozoa varied. All enzymes, except N-acetyl glucosaminidase, were shown to decrease after injection of toad pituitary extract and they were also found to be absent from testis containing no spermatozoa. The glycosidases were found to act on toad oviduct jelly and they may therefore be involved in the degradation of the jelly after fertilization, into smaller bits, which may be utilized as nutrients by the fertilized zygote.Acknowledgment. We thank Prof. T.R. Ramaiah, Head of the Department of Biochemistry, University of Mysore, for his help. We also acknowledge the financial assistance of University Grants Commission to one of us (MS) and CSIR through a grant No. 9 (165)83/EMR-II to HSS. Please address all correspondence to H.S. Seshadri.     

Effect of photoperiod and all-female grouping on the estrous cycle of the bandicoot rat,Bandicota bengalensis

Summary Female bandicoot rats showing irregular cycles in 12L12D, were exposed to light-darkness cycles of 1L23D, 4L20D and 8L16D. Significant regularization of the estrous cycle was observed in 8L16D with most of the rats exhibiting a regular 3-day cycle and the regularity was further enhanced by all-female grouping (4/cage).     

Experiments on the sense of time inTalitras saltator (Montagu) (crustacea-amphipoda)

Riassunto Il Crostaceo AnfipodeTalitrus saltator (Montagu) possiede un meccanismo di orientamento solare che gli permette, mediante una variazione regolare e continua dell'angolo di orientamento nel corso del giorno, di mantenere una direzione di fuga praticamente costante. Esemplari del litorale tirrenico, trasportati in Argentina, hanno assunto un angolo di orientamento col sole conforme all'ora italiana nel momento della esperienza. Ciò dimostra che la regolazione dell'angolo di orientamento è dovuta ad un fattore endogeno e cioè che esiste inTalitrus un senso del tempo.     

Level of ascorbic acid and its oxidation in the liver of the scorpion,Palamnaeus bengalensis

Zusammenfassung Kolorimetrische und manometrische Untersuchungen zur Konzentrationsbestimmung der Ascorbinsäure und ihrer Oxydationsrate in der Skorpionsleber beiPalamaeus bengalensis.     

Studies on the growth ofPrymnesium parvum carter (chrysomonadina) and on the formation of its toxin (prymnesin)

Résumé Prymnesium parvum Carter atteint sa taille maximale en 9–10 jours et produit une grande quantité de toxine, quand il est cultivé à la lumiére dans un milieu comprenant des sels, du glycérol et certains acides aminés (sérine ou -alanine).

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Part of a Ph.D. thesis, submitted to the Faculty of Science, The Hebrew University, Jerusalem.