Fig. 5. Comparison of finished capsules with capsules intercepted before passage into the ventral pedal gland (VPG) for three species of prosobranch whelks. In each case, the unfinished or `immature' capsule is located on the left. (A) Kelletia kelletii, (B) Chorus giganteus (courtesy of J. Ram, Wayne State University) and (C) Busycon canaliculatum. Finished capsules have the characteristic mechanical properties as well as a yellow tint. `Immature' capsules are rough approximations of the final shape of the capsule. `Immature' capsules are soluble in common protein denaturants and lack any significant cohesion when strained. Scale bars, 0.5 cm.