Life Sciences Commons^™

Comparative Aspects Of Mammalian Spermiogenesis, Leif Plöen, Jean-Luc Courtens

Scanning Electron Microscopy

The testes of some different orders of eutherian mammals were examined by conventional electron microscopy with respect to their pattern of spermiogenesis. In addition, some of the testes were studied by cytochemical methods for demonstration of certain nuclear proteins and of glycoproteins in the acrosome and the plasma membrane of spermatids.

It was found that although the basic pattern of spermiogenesis was similar in all species studied, there were pronounced dissimilarities in the final shape of the spermatids. Differences were also observed in the timing of the differentiation of several organelles. The head of late spermatids and spermatozoa of Primates, …

Functional Aspects Of Renal Glomeruli Based On Scanning Electron Microscopy Of Corrosion Casts, With Special Emphasis On Reptiles And Birds, H. Ditrich, H. Splechtna

Scanning Electron Microscopy

The glomerular complexity of several species of birds and reptiles is investigated in this study by scanning electron microscopy of vascular corrosion casts. Comparing these results with those of a freshwater teleost and a mammalian species, a trend towards small, simple glomeruli of the avian type, beginning with large, well vascularized glomeruli resembling the type found in fish, can be observed in reptiles.

A close correlation between glomerular size and habitat can be established comparing related species having a similar physiological mode of renal function.

Entirely different from this sauropsidian evolutionary line of development is the highly complex, large differentiation …