Ontogeny of the Behavior of Strombus maculatus (Gastropoda: Strombidae)

The ontogeny of strombid behavior was studied by observing thebehavior of Strombus maculatus veligers collected from the planktonand reared past metamorphosis to adults, and by observing juvenilestrombids collected in the field. Complete adult modal actionpatterns (MAP's) associated with locomotion, feeding, and rightingof overturned shells are performed by S. maculatus juvenilesimmediately after metamorphosis. There are changes in the frequencyof the use of certain MAP's which are associated with variationsin shell shape and size. The unique strombid escape response to molluscivorous gastropods(Conns spp.) is not released until juvenile S. maculatus arethree weeks past metamorphosis and two millimeters in shelllength. At that stage, the complete response is released uponthe first encounter with a predator. Experience with a predatordoes not seem to lower the age or size criteria. During ontogeny there is a trend toward an increasing complexityof behavior which is paralleled by an increasing complexityof neural structure and general morphology. There are majorsteps in the ontogeny of strombid behavior which probably coincidewith neural and morphological stages.     

Malarial Parasites of the "Jesu Cristo" Lizard Basiliscus basiliscus (Iguanidae) in Panama

SYNOPSIS. The iguanid lizard Basiliscus basiliscus in Panama is parasitized by Plasmodium basilisci and P. achiotense sp. nov. P. basilisci in this host is characterized by schizonts containing 4–14 merozoites, with schizonts parasitizing proerythrocytes containing more merozoites than those in erythrocytes. Asexual parasites lack cytoplasmic projections, while mature gametocytes are round or oval with regular margins.
P. achiotense is characterized by the combination of prominently pigmented, large schizonts containing 36–56 merozoites and oval or round gametocytes which are about 1/3 larger than those of P. basilisci.
EE-schizonts of P. basilisci were observed commonly in thrombocytes and occasionally in lymphocytes, and appeared early in experimental infections induced by blood inoculation.     

A New Saurian Malarial Parasite Plasmodium balli from Panama

SYNOPSIS. Plasmodium balli sp. nov. is described from Anolis lionotus and A. poecilopus of central Panama.
Large, elongate gametocytes and segmenters containing up to 100 merozoites are produced by P. balli. Proerythrocytes and normoblasts are more commonly parasitized than erythrocytes. Pigment is uncommon, but when present consists of a minute dot. Hypertrophy, distortion and lysis of host cell nuclei may result from parasitization of immature blood cells by gametocytes, while enucleated host cells are common.     

The Control of Color in Mammals

SYNOPSIS. Recent advances in the biology of mammalian pigmentationare reviewed.Particular attention is given to emerging informationon the integration of pigmentary events occurring at differentlevels of biological organization within mammalian skin andhair. The structural and functional significance of keratinocytesand melanocytes as components of mammalian epidermal melaninunits is viewed from this perspective. New evidence on the natureof genetic, developmental, endocrine, and radiation influenceson performance of melanocytes and the establishment of pigmentarypatterns is summarized.     

HISTOLOGICAL AND HISTOCHEMICAL CHANGES IN DEVELOPING AND RIPENING PEACHES. I. THE CATECHOL TANNINS

Reeve , R. M. (U.S.D.A., Albany, California.) Histological and histochemical changes in developing and ripening peaches. I. The catechol tannins. Amer. Jour. Bot. 46(3) : 210-217. Illus. 1959.—Selective histochemical tests for catechol derivatives revealed marked changes in tannin contents during the development and ripening of peaches. The principal test used was a nitroso reaction found to be colorimetrically selective for catechol and derivatives such as chlorogenic acid. Intensities of color produced by this test were photometrically measured. Increases in catechol derivatives, so indicated in situ, were associated with early maturation and lignification of the endocarp sclereids and particularly with cessation of cell divisions and early cell enlargement of the mesocarp parenchyma. Characteristic progressive localizations of tannins in patches of enlarging mesocarp parenchyma cells, as revealed by staining with iron salts as well as by the nitroso reaction, were observed in green fruits approaching maturity. The insoluble tannin color complexes produced by these tests remained coarsely granular and intense in green fruit. Upon ripening of the fruit color intensity produced by the nitroso reaction decreased and the insoluble tannin complexes were more finely divided. The association of phenols with cellular differentiation, lignification and suberization are briefly discussed.     

The Catabolism of Plasma Albumin in the Rabbit : Its rate and regulation

From I¹³¹-albumin studies and previously defined mathematical formulations, rates of breakdown were estimated for native plasma albumin in rabbits. These rates of catabolism per unit weight of animal were remarkably constant and were independent of variations in the steady state values of albumin concentration in the plasma. These results imply that, at least between animals, the breakdown of plasma albumin follows a kinetic process of approximately zero order. It seems plausible that the process operates similarly in individual animals, and hence that albumin is maintained at normal steady state levels in the healthy animal primarily by means of a regulated rate of synthesis.