|
Collar cells occur in |
|||
|
(a) |
sponges |
(b) |
hydra |
|
(c) |
sandworm |
(d) |
starfish |
|
Collar cells occur in |
|||
|
(a) |
sponges |
(b) |
hydra |
|
(c) |
sandworm |
(d) |
starfish |