What are the thin tubes that form between the centrioles during mitosis?

The thin tubes that form between the centrioles during mitosis are the spindle fibres. Spindle fibers originates from a protein structure that divides the genetic material in a cell. They are necessary for the equal division of the chromosomes in a parental cell into two daughter cells during bth types of nuclear division (mitosis and meiosis). During the process of mitosis they are called mitotic spindles.