The present study was undertaken to determine, by measurement
of nuclear DNA, the degrees and frequencies of ploidy in the
last larval instar of the moth Galleria mellonella Linnaeus. While
such data have been amassed for a wide variety of vertebrate tissues,
few studies have been concerned with invertebrates and...
(Brandt) were surveyed for the presence of polyploid cells.
Large polyploid cells were found in the hepatic cecum, gut
and sheath of the testis.
The relative DNA content of the polyploid nuclei was
measured by means of two wavelength cytophotometry. Histograms
plotted from the data provide information on the level...
This study was initiated to determine the concentration
of magnesium and calcium in dividing eggs of the sea
urchin Stroncavocentrotus purpuratus and to explore the
relationship between these ions and mitotic events.
Samples of developing eggs, maintained at 15°C, were
taken at ten-minute intervals from fertilization through
the second cleavage,...
The epidermis of the brook lamprey, Lampetra planers
(Bloch), has been examined with histological and histochemical
techniques and the fine structure of the fibrillar
club cells has been studied with electron microscopy.
In histological structure the epidermis was found to
correspond to the observations of earlier workers. The
stratified epidermis...