` Must ' elephants are males in a condition of - probably sexual - excitement, when an abundant discharge of dark oily matter exudes from two pores in the forehead.
2, b.c. l) is unpaired, and opens to the exterior by the two proboscis pores (p.p.).
3, c p.) are a pair of ovoid organs which open from the collar-cavity to the exterior, their external pores lying immediately behind the base of the operculum.
While it is not improbable that the collar-pores and the proboscispores may evacuate excretory substances, there can be little doubt that their primary function is to regulate the turgidity of the segment to which they respectively belong.
8), seen in solid tentacles as a row of cubical vacuolated cells, occupying the axis of the tentacle, greatly resembling notochordal tissue, particularly that of Amphioxus at a certain stage of development; as a fourth variety of endodermal cells excretory cells should perhaps be reckoned, as seen in the pores in the foot of Hydra and elsewhere (cf.
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