摘要:

AbstractThe anatomy and histochemistry of the sympathetic nervous system in the cod were studied by osmic acid staining, cholinesterase staining and fluorescent histochemistry of ganglia and nerve fibres. Large bundles of fluorescent fibres from the sympathetic ganglia in the head enter the cranial nerves and run with these. These bundles are exceptionally large to the vagi, and the cod vagi may therefore be regarded as vago‐sympathetic trunks. All the sympathetic ganglion cells contain specific (acetyl‐) cholinesterase, although the degree of staining was variable. The vast majority of cells in the ganglion coeliacum and other anterior ganglia show specific fluorescence of variable intensity. Ganglion cells completely devoid of specific fluorescence are scarce in the anterior ganglia, but abundant in the posterior ganglia associated with the vesicular nerve. A separate and distinct bundle of medullated fibres leaves the sympathetic chain on the left side and spreads in the wall of the left posterior cardinal vein, presumably innervating the chromaffin tissue. Similar fibres on the right side are also present, but do not form a distinct ne

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1976.tb00212.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractThe eggshells of the cormorant (Phalacrocorax carbo), domestic fowl (Gallus domesticus), gannet (Sula bassana), guinea fowl (Numida meleagris), greater flamingo (Phoenicopterus ruber), and shag (Phalacrocorax aristotelis) have been separated into two groups on the basis of the composition of their outer stratum. In the domestic fowl, guinea fowl and greater flamingo the outer stratum is an organic cuticle while in the sea‐birds it is an inorganic cover rich in vaterite. The calcareous deposits on the membranes of eggs of the domestic fowl which are shell‐less at oviposition have been shown to consist essentially of the vaterite form of calcium carbonate. Reasons for the occurrence of this polymorph of calcium carbonate are discussed with relation to the physiology of the bi

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1976.tb00213.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractHeterophilic granulocytes were studied in the blood, intestinal wall, and islet parenchyma of the Atlantic hagfish (Myxine glutinosa) by light and electron microscopical methods. The granulocytes are pseudoeosinophils and show a PAS‐positive cytoplasmic reaction. Ultrastructurally, the cells contain evenly distributed pleomorphic cytoplasmic granules with the granule membrane close to the osmiophilic core. Emigrated blood granulocytes are found extra‐vascularly in the submucous connective tissue, and obviously they can pass the basal lamina and migrate into the epithelium of the intestine, bile duct, and islet parenchyma.Though the staining characteristics of hagfish granulocytes are different from those of endocrine cells in the intestinal mucosa and islet parenchyma, intraepithelial granulocytes in some locations may sometimes be difficult to distinguish ultrastructurally from insulin‐containing B‐cells, since heterophil granules have both a size and a shape close to those of secretion granules in B‐cells. However, in contrast to B‐cells the granulocytes show the following ultrastructural features: a lobated nucleus with peripherally arranged electron‐dense chromatin; cytoplasmic processes and often rod‐like granules with no clear space between the granule membrane and core; prominent cytoplasmic vacuoles and microtubules; and sparse mitochondria and endoplasmic reticulum. Furthermore, immigrated granulocytes lack desmosomes and annulate lamellae.Some of the intraepithelial granulocytes in the mucosa show signs of disintegration and cell death. Degenerative cell processes are also described in the i

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1976.tb00214.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractMorphometric measurements have been made on various gill components of different stages in the life cycle of the anadromous parasitic lamprey,Lampetra fluviatilis, and its nonparasitic derivativeLampetra planeri.The total gill area, expressed in terms of body weight, of both larval (1462–2717 mm2g–1) and adult (1402–2337 mm2g–1)L. fluviatilisare greater than those previously recorded in the rather meagre literature on lamprey gill measurements and are comparable with those found in the most active teleosts. The gills of the twoLampetraspecies are apparently identical in the larval stages and those of metamorphosing and adultL. planeriare similar to those of metamorphosingL. fluviatilis.Although the pharyngeal arrangement of lampreys differs greatly from that of teleosts, there are many features of the gills indicative of convergence between the two groups. Thus, in a given stage in the life cycle of lampreys, the secondary lamellae on either side of the filaments also alternate, become more widely spaced as the filament length increases and increase in area as the body weight becomes greater. Furthermore, the fractional cumulative increase in secondary lamellae area along a line following the presumed direction of water flow is also represented by a sigmoid curve.While at metamorphosis the pharynx becomes considerably modified to accommodate the change from a unidirectional to a tidal respiratory water flow, the total gill areas of the ammocoete are similar to those of metamorphosing stages which have attained adult characteristics. However, there are clearly differences in some of the components that influence and contribute towards the total gill area. Thus, in terms of body weight, the number and total length of the filaments and the total number of secondary lamellae, together with the number of secondary lamellae found on a given distance of filament, are greater in late metamorphosing stages, while the reverse is true for the average bilateral area of the secondary lamellae which is considerably greater in amm

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1976.tb00215.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

AbstractScanning electron microscopy and the Bodian protargol technique are applied to the cell body of a tintinnid for the first time. The somatic ciliature, the membranelles, the pulsating vacuole, the preoral cavity and the invagination at the posterior end of the cell body are demonstrated for the speciesParafavella denticulata(Ehrenberg 1840). The correlation between SEM and the protargol impregnations is striking, and the presumptive taxonomic and phylogenetic value of these methods for the study of tintinnids is emphasized.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1976.tb00216.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1976.tb00217.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY