RATE OF RESPIRATION AS RELATED TO AGE

In the present paper it is shown that as the leaves of corn, sorghum, wheat, and oats increase in age there is a decrease in rate of respiration; but that as the leaves become still older (past about middle age) the rate gradually increases.     

Antibodies that recognize phosphodiester-linked amino-N-acetylglucosamine-1-phosphate residues

An affinity chromatography procedure was developed for isolating antibodies that recognized phosphodiester-linked alpha-N-acetylglucosamine-1-phosphate (alpha-GlcNAc-1-P) residues. The affinity resin consisted of uridine-5'-diphospho-alpha-N-acetylglucosamine (UDPGlcNAc) conjugated to Sepharose. Antiserum prepared against Proteinase 1 from the cellular slime mold, Dictyostelium discoideum was used as a source of the anti-alpha-GlcNAc-1-P antibodies. Immunoblot assays showed that the affinity-isolated antibodies recognized phosphoglycosylated subunits of Proteinase 1, and that UDPGlcNAc blocked this interaction.     

Oogenesis in the Apogamous Fern Pteris cretica

The events that characterize egg formation and maturation inPteris cretica were investigated using transmission electronmicroscopy and electron microscope microprobe analysis. Theydid not differ significantly from those described for sexuallyreproducing ferns. The significance of these findings is discussedin relation to current theories concerning phase change in ferns. Pteris cretica, fern, apogamy, agamospory, transmission electron microscopy, oogenesis