The Thymus gland.

The thymus and the pineal gland regress after childhood the pineal is between ages 1-5 and the thymus regresses after puberty.

T cells mature in the thymus The T-cells mature in both the thymus gland and the organs known as tonsils.

The thymus is an organ in the upper chest, which all mammals have. The calf thymus is a thymus that belongs to a calf. Calf thymus DNA, is the DNA that can be isolated from this calf thymus. Calf thymus DNA is used for many experiments, because the thymus has a very high yield of DNA (calf thymus DNA has a yield of approx. 2.542% (w/w))

thymus