Age, Change and the Adapted Life: DR. WM. DE B. Special Articles: MACNIDER.415 At Filterable Virus Isolated fromn a Case of M A ND R. .......................................................................................................... 1 it r b e ' i u s l t d f o a e o Kaposi's Varicelliform Eruption: DR. RUSSELL J. Obituary: BLATTNER, DR. FLORENCE M. HEYS and DR. MARY RobertlAnthony Hatc...

The pollen of five diploid and two tetraploid guayule (Parthenium argentatum Gray) plants was cultured on nutrient media. It was observed that guayule pollen is released as tetrads of spores which will not ger­ minate on the media unless they are separated into individual pollen grains. For each plant, the results of the germination tests varied with the day and the time of day of the pollen co...

The fragility of a single-source, geographically concentrated supply of natural rubber, a critical material of the modern economy, has brought guayule ( ​Parthenium argentatum​ A. Gray) to the forefront as an alternative source of natural rubber. The improvement of guayule for commercial-scale production has been limited by the lack of genomic tools and well-characterized genetic resources requ...

The rubber-producing tree, Ficus elastica (the Indian rubber tree), requires the same substrates for rubber production as other rubber-producing plants, such as Hevea brasiliensis (the Brazilian or Para rubber tree), the major source of commercial natural rubber in the world, and Parthenium argentatum (guayule), a widely studied alternative for natural rubber production currently under commerci...