What are the differences between xylem and phloem?

I got this from http://wiki.answers.com/Q/The_structure_and_function_of_xylem_and_phloem

Xylem - The function of xylem vessels is to transport water, minerals and inorganic ions in the plant, and to provide support for the plant. The xylem is adapted to this function by being hollow and elongated, so that they can carry as much water as possible. They are dead cells, so have no cell contents of their own, maximising space for water and dissolved substances to be transported. The xylem vessels are continuous and end-walls between cells break down, and this means that there is nothing to impede transport. The walls of the xylem vessels are lignified (coated with lignin) and lignin may be annular (ring form), spiral or reticulate. This strengthens the xylem and allows it to withstand the tension created by the transpiration pull. Pits are present in the cell walls to allow the lateral movement of water. Xylem vessels also have narrow lumens, which allows water to be drawn to a greater height by cappilarity.

Phloem - The function of phloem is to transport sucrose and other soluble assimilates and organic substances. Phloem is made up of sieve tube elements which are joined end-to-end to form long tubes. These are living, but have no mitochondria, nucleus or golgi apparatus and no ribosomes. This is an adaptation so that the lumen for transport of sucrose etc. is larger and there is less obstruction to the flow of liquid in the phloem. The end walls of the sieve tubes are perforated and these perforated end walls are called sieve plates. Pores in the sieve plats offer less resistance to flow of liquid. Sieve tubes are always associated with companion cells which are also living and have a dense cytoplasm with all the organelles and a thin cellulose cell wall, which means that materials made in the companion cell can easily pass out into the sieve tube. The sieve tube cannot survive without the companion cell. The companion cells have many mitochondria to make ATP for active transport - another adaptation. Cellulose in the cell walls provides strength to prevent the sieve tubes bursting when under pressure.

xylem conducts water in a plant while phloem conducts food in a plant