What is the nature of the viscous yellow pieces that are discharged with semen, and is it permissible to masturbate by hand or otherwise to examine semen?

The yellow specks that appear with the aforementioned fluid are part of theen semen. A woman's semen is thin and yellow. If this is from a man, it may indicate an illness. Masturbation for a man by a woman other than his wife is unlawful, unless it is determined to be a means of treatment. However, by his wife, it is permissible.