<span>Yes, if the photo receptor cells and simple eyes that preceded it were useful to the animals in which they arose.</span>
<span>The ventricular system consists of four ventricles that are interconnected in the brain.
The third ventricle</span> is the portion of the ventricular system is found within the diencephalon. It is a median cleft in the diencephalon between the two thalami, and is filled with cerebrospinal fluid (CSF).
The hypothalamus is the gland located within the floor of the this ventricle.
The Incubator made it possible to maintain a controlled environment for cell cultures because most modern incubators act as a petri dish but in a more controlled state.
