摘要:

SYNOPSISThe mean number of eggs ovulated was found to be 10.0 eggs per hamster, range 3 to 17. The fertilization rate was 85.7 p.c. In eggs recovered shortly after ovulation the mean overall diameter was 117.8μ, the thickness of the zona pellucida was 11.6μ, and the diameter of the vitellus was 73.2μ in unpenetrated eggs and 70.9μ in penetrated eggs. The first polar body always persisted until after ovulation. When the second maturation spindle could be identified it was always in metaphase in unpenetrated eggs examined soon after ovulation. The hamster egg has an unusually large perivitelline space.The zona pellucida dissolved in acid solutions at pH 2.8 and lower; it was readily digested by trypsin solutions, the zona from penetrated eggs being a little less resistant than that from unpenetrated eggs. The zona may undergo expansion during cleavage and was often lacking from eggs in the 4‐cell and later stages.When hamsters were kept from birth or weaning under controlled illumination (light from 4.0 p.m. to 7.0 a.m., dark from 7.0 a.m. to 4.0 p.m.), ovulation occurred chiefly between 2.0 p.m. and 4.0 p.m. There was a delay of approximately 2 hr. between ovulation and spermatozoon penetration.With natural lighting (July to September), nearly half the eggs recovered at 7.0 p.m. were in stages immediately preceding the first cleavage. On the next day (day 2) all fertilized eggs were 2‐cell, on day 3 they were 3‐ to 8‐cell, and on day 4 they were morulæ or early blastocysts.The process of fertilization is briefly described and compared with that seen in rat and mouse eggs. The male and female pronuclei resemble each other in size and form and are often indistinguishable. When one pronucleus is larger than the other it is probably the male. In nuclear and nucleolar dimensions the hamster egg resembles the mouse egg rather than the rat egg.In 519 penetrated eggs the incidence of polyspermy was 1.08 p.c. Not one of the penetrated eggs, however, had a supplementary spermatozoon. The zona reaction in the hamster egg is therefore very‐rapid and may constitute the only protection against polyspermy.Six eggs presenting anomalous features are described.Results are discussed in relation to previous observations on the hamster and

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00421.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

SYNOPSISThe effect of injecting mice with 1 ml. each of a saturated solution of neutral‐red chloride in Ringer's solution was studied before making an attempt to determine the origin, identity, and function of neutral‐red bodies in acinous cells of the pancreas.The existence of a neutral‐red “granule” cycle was confirmed. This was partly divided into two main phases: phase I, in which there were a few homogeneously staining granules and phase II, in which there were large numbers of homogeneously staining granules and vacuoles.The neutral‐red granules seen in phase I of the cycle appeared to correspond with granular lipoidal bodies observed either in cells of the same pancreas or in cells of normal (not coloured with neutral red) organs. The neutral‐red granules and vacuoles seen in phase II of the cycle were shown to correspond with granular and vacuolated lipoidal bodies recognized in cells of the same pancreas. In neither phase I nor phase II of the cycle were neutral‐red vacuoles observed amongst zymogen granules. However, vacuolated lipoidal bodies were seen in this position in cells previously coloured with neutral red or in normal cells. All these results are consistent with the view that neutral red first colours preexistinggranularlipoidal bodies and is then responsible for the formation of new lipoidal bodies (granular and vacuolated).The neutral‐red bodies were observed to originate in contact with mitochondria. They then passed towards the zymogen zone. In both respects they resemble lipoidal bodies of normal cells.In normal cells lipoidal bodies probably segregate and synthesize substances needed for the formation of zymogen. In cells coloured by neutral red the lipoidal bodies segregate the dye and appear no longer to form zymogen. It would seem that in the latter instance the lipoidal bodies act in a protective capacity and protect the acinous cells from the injurious effects of neutral red. This suggests that under the sustained influence of neutral red, the lipoidal bodies, and therefore the cells, may be deviated from their normal function of synthesizing zymogen.The observations in normal cells that lipoidal bodies originate from mitochondria and then accumulate on the walls of Golgi canals before completing zymogen synthesis, suggests that the Golgi apparatus makes some contribution to lipoidal bodies that enables them finally to comple

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00422.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

SYNOPSISA preliminary report is given of observations made on the neurones of the pedal ganglia ofPatella vulgata.Three types of cytoplasmic inclusions have been seen in these cells—mitochondria, lipochondria, and Golgi apparatus. The dictyosomes described by other workers probably correspond to pairs of Golgi membranes together with the dense (osmiophilic) substance they enclose. The archoplasm probably corresponds to numerous small Golgi vesicle

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00423.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

SYNOPSISA résumé is given of the literature on the morphology of collagen fibre bundles, and the occurrence in them of elastin, reticular tissue, and a cement substance. Two methods of demonstrating reticular tissue have been investigated.(1)Silver impregnation.A number of variations of the technique have been tried, and Foot's balanced solutions method has been adopted as the most satisfactory for skin. It gives clear, sharp preparations, in which (after toning with gold) collagen becomes rose‐red to rather purple in colour, and reticular tissue usually shows black. The fine binding fibrils around collagen fibre bundles did not stain as elastin, nor did they become black when impregnated with silver. Nevertheless, they are considered to be reticular tissue, since morphologically they resemble reticulin more closely than they do collagen.(2)Swelling of fibres.Fibre bundles teased from the skin of cattle (calf and ox) and sheep (3–18 months) were soaked at a range of pH values in hydrochloric acid solutions. Calf fibre bundles from the leg swelled more readily and at higher pH values than those of the ox from the same position, in which the restrictive binding tissue was present as an intermittent sheath. The collagen fibres twisted into a rope‐like form and became entangled in the associated elastin fibres, which, therefore, played an important part in restricting the fibre bundles as they swelled. It is also inferred, though the investigation was not specially directed towards this point, that a cement substance is present, holding the collagen fibres into bundles even in the absence of reticular tissue and

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

摘要:

SYNOPSISThe following notes describe some newMastogloiafound in the district around Karachi and report on observations made concerning the development of the frustule in that genus during cell division.

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1955.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1955

数据来源: WILEY