Male albino rats, approximately 200 gm. in weight, maintained on Fox Blox food (Allied Mills Co.) with water ad libitum were used. The rats were divided into 7 groups of 20 each; 10 of each group were irradiated and 10 were used as controls. Neutron irradiation was performed as described by Enns (3). Groups 1 to 5 were given 56 n and tissues were removed for examination at the following interva...

Basophilic and eosinophilic tissue components are difficult to demonstrate by stains commonly used in light microscopy after osmium tetroxide fixa-tion. Baker (2) states that "if only chromatin were left in a state in which it could be differentially stained without difficulty, this fixative would be universally recognized as superior to all others" for light microscopy. The difficulty encounte...

Certain morphological characters of mammalian spermatozoa have been shown to have a high heritability (Beatty, 1970). Sperm dimensions may be altered by genetic selection (Woolley, 1970). In addition to the biological action ofthe genes, the actual mass of the DNA and proteins, which constitute the major components of the head, may affect the sperm phenotype. Unlike genetically active cells in ...

The redclaw freshwater crayfish Cherax quadricarinatus has a reputation for being hardy and resistant to handling stress. However, in recent years, possibly since 1996, C. quadricarinatus farmers in northern Queensland have noted a decrease in stress resistance in their stock. A presumptive reovirus in the hepatopancreas, and a putative parvovirus in the gills, were associated with chronic mort...