Pollen tube through wind, water or pollinators. The last step before fertilization is the growth of the pollen tube to transfer non-motile sperm to the protected egg. Pollen tubes are unique to plants and their structure had evolved over plant history. The pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists. Pollen is produced by the stamen, the male reproductive organ of the flower. Each pollen grain contains a vegetative cell, and a generative cell that divides to form two sperm cells. The pollen is delivered by the opening of anthers for
Shroud of Turin should be suspended until a new collection of pollen grains can be carried out and the grains thus obtained can be studied with modern equipment and by an expert of pollen of this area." Skeptics have argued that the flower images are too faint for Danin's determination to be definite, that an independent review of the pollen strands showed that one strand out of the 26 provided contained significantly more pollen than the others, perhaps pointing to deliberate contamination. Skeptics also argue that Max Frei had previously been duped in his examination of the Hitler Diaries and that he may