Pollen tube Pollen tube A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. It acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than to traverse the length of the pistil. Pollen tubes were first discovered by Giovanni Battista Amici. They are used as a model for understanding plant cell behavior. Research is ongoing to comprehend how
The X from Outer Space Guilala is finally defeated by jets laden with bombs, which coat it in a substance called "Guilalalium." It causes Guilala to shrink down to its original spore form. The government promptly launches the spore back into space, where it will circle the sun in an endless orbit. "The X From Outer Space" was released in Japan on 25 March 1967. "The X From Outer Space" was never released theatrically in the United States, and was released directly to television by American International Television in 1968. The Criterion Collection released "The X from Outer Space" on DVD in a compilation titled