In the living condition (found in sea) you would be able to observe the following features in radiolarians:

The cytoplasm is divided by a perforated and chitinous metnbrane into an inner medulla or intracapsular region, containing one or more nuclei and oil globules, and an outer cortex or extracapsular region which sometimes contains yellow symbiotic algae

Each example represents a zooid of a colony, having a single nucleus. When these organisms die their skeletons sink to the bottom of the sea and Sonn rsdiolarian ooze.

Place a permanent slide of radiolarian ooze under tlie Microscope and observe it:

i) 1n many radiolarialis a hard, transparent, symmetrical skeleton is present

ii) The skeleton may be consisting of silicon or strolitiutn sulphale, and imparts different shapes to these organisms.

iii) The opening of the skeleton is extended in the form of fine, stiff ray-like pseudopodia.