Silica in the Mesophyll Cell Walls of Italian Rye Grass (Lolium multiflorum Lam. cv. RvP)

Isolated cell envelopes from the leaf mesophyll of Italian ryegrass were examined in a transmission electron microscope equippedwith an energy-dispersive X-ray spectrometer. Silicon was detectedin these walls at an estimated concentration of 1–2 percent. Samples were also subjected to a range of techniques,for the removal of organic matter, which confirmed the presenceof silica throughout the cell walls. Lolium multiflorum Lam, Italian rye grass, cell walls, silica, electron microscopy, X-ray microanalysis     

Environmental Influences on Thyroid Function in Teleost Fish

SYNOPSIS. A brief account of some of the influences that environmentalfactors, such as the lunar cycle, daylength and temperature,may have on thyroid activity in certain salmonids and the killifish,Fundulus heteroclitus, is presented. The rapid and immediatecharacterof temperature effects is discussed and a role for central neuroendocrinecontrolin mediating the effects of photoperiod and lunar phenomenainvolvement is suggested.