摘要:

AbstractAn examination of the trophosome of a mermithid nematode (Gastromermissp.) revealed large aggregates of dense tubular rods in the cytoplasm. These rods were 18nm in diameter and variable in length. They were apparently formed in the trophosome and may represent a unique form of nutrient reserve. Other aspects of trophosome morphology are described.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00760.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractTwo methods of age determination in newts.Triturus vulgarisandT. cristatus, have been examined and compared: (1) Counting growth rings in the bone tissue of humerus or femur is an accurate method, but possible supplementary rings may make the reading difficult. The innermost periosteal zone corresponds to the first year of life. Later, new zones are added each year. (2) Every second year after maturing a new lobe is developed on the testes. Knowing the juvenile life span in a population, it is possible to determine the age of male newts with a possible error of one year. The correlation between growth marks and testis lobes inT. vulgarisandT. cristatusis highly significant. The testis lobing method, however, is less applicable in older newts, since no more than three or four lobes can be developed on a testis.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00761.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractIn smooth muscle cells forming parts of the testicular wall in the European fire salamander,Salamandra salamandra, phagosomes have been found which contain collagen fibres in different stages of decomposition. As a rule, these cells occur in the regressive glandular part of the testis.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00762.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe morphology of the hitherto unknown larva ofPyura tessellata(Forbes) is described and the discovery of an auxiliary brain vesicle is presented. The vesicle was also found in another pyurid speciesBoltenia echinata(L.). The auxiliary vesicle communicates with the sensory vesicle at the level of the statocyte and is lined with cubodial epithelial cells carrying a 2 μm globular structure projecting into the lumen. These cells very closely resemble primitive tunicate coronet cells previously reported and coronet cells typical for the saccus vasculosus found in elasmobranchs and many ganoids and teleosts

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00763.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractPerl's Prussian blue and bathophenanthroline have been used to investigate the sites where iron‐containing granules are found within representatives of each of the three extant families of lampreys. Amongst the larvae, granules were present in the columnar cells of the posterior intestine in small amounts in some but not all northern hemisphere species (Petromyzonidae), and in moderate and very large amounts in the southern hemisphere families Geotriidae and Mordaciidae respectively. Granules were only found in large numbers elsewhere in the body of larvae of the Geotriidae, in which they were predominant in the adipose tissue of the nephric fold and fat column. It is suggested that these large iron deposits reflect the intake of an unusually large amount of iron, a feature which in turn could be related to the relatively high plasma iron levels and haemotocrit found in larvae of the Geotriidae. During metamorphosis, iron deposits accumulate in the liver of all species as haemoglobin is broken dow

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00764.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractTransmission electron microscopy revealed varying morphology of the dorsal part of the duct indicating the occurrence of different stages of activity. In some animals the tip cavity contains an amorphous substance which, at another phase of activity, is released into the surrounding hemocel through interstices in the walls of the tip. A transitional zone separates the dorsal tip from the large ventral part of the duct, where the wall, near the transitional zone, consists of a single layer of thin cells joined by tight junctions. Ventrally, the large ciliated cells lie in two levels near the opening into the buccal cavity. They bear numerous, tightly packed cilia which beat vigorously in living animals. The organization of this part resembles that of protonephridia. An excretory function is suggested for this part of the duct.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00765.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractParallel observations on synaptic and neurohaemal terminals in the polychaete annelidsNereis diversicolorandHarmothoe imbricatahave revealed a remarkable identity of ultrastructure. Even features peculiar to the synaptic vesicles of polychaetes are mirrored by those of synaptoid inclusions. A wide range of terminal types show a clear duality of secretory inclusions, featuring both ‘storage granules’ and synaptic/synaptoid vesicles. The inclusions exhibit a marked zonation. Vesicles form tight clusters with interstitial dense material in many terminals and these make contact with release sites. Terminals containing larger, typically peptidergic granules often have mainly dense‐cored synaptic/synaptoid vesicles, although some such inclusions are present in other endings also. A variety of synaptic associations are present, and ‘serial synaptoids’ are formed by neurohaemal terminals. The results are interpreted to suggest that synaptic and synaptoid vesicles have a common functional sig

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1982.tb00766.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY