Xylem cells are elongated cells with lignified secondary thickening of the cell walls. Xylem cells are specialised for conduction of water, and first appeared in plants during their transition to land in the Silurian period more than 425 million years ago (see Cooksonia). The possession of xylem defines the vascular plants or Tracheophytes.
hobo. a hobo is an itinerant worker, a career which sprang up during the depression. A hobo, unlike a bum or a tramp, is more than willing to work, but mostly for a short duration, as their main impetus is travel, the love of the journey above the actual destination.
(November 2009). Sambo is a term for a person with African heritage and, in some countries, also mixed with Native American heritage (see zambo). A painting captioned Negro con Mulata produce Sambo (Negro with a Mulatto produces a Sambo), Indian school, 1770.he word sambo came into the English language from the Latin American Spanish word zambo, the Spanish word in Latin America for a person of mixed African and Native American descent. This in turn may have come from one of three African language sources.