. The elementary nervous system . Fio. 5.—Radial portion of a transverse section of Stylotella; the flesh of the sponge is dotted, the cavities are undotted; on the extreme left is the dermal membrane pierced by two pores p that lead into a large subdermal space s, from which incurrent canals i lead to the flagellated chambers /, which in turn open by excurrent canals e into the cloaca c. ditiou to the water of some such substances as carmine, starch, or indigo, whose particles could then be followed as they were carried in the moving water. Latterly this method has been severely criticized by
. The elementary nervous system . Fio. 5.—Radial portion of a transverse section of Stylotella; the flesh of the sponge is dotted, the cavities are undotted; on the extreme left is the dermal membrane pierced by two pores p that lead into a large subdermal space s, from which incurrent canals i lead to the flagellated chambers /, which in turn open by excurrent canals e into the cloaca c. ditiou to the water of some such substances as carmine, starch, or indigo, whose particles could then be followed as they were carried in the moving water. Latterly this method has been severely criticized by von Lendenfeld (1889), who claims that even these small suspended par- ticles mechanically stimulate the sponge and cause it to close its pores. Von Lendenfeld used milk as an indi- cator and found no objection to it. With Stylo fell a it is easy to demonstrate the pore currents with can nine and the like, and, so far as could be discerned, this material could be used without causing partial closure of these apertures. In fact, as stated by Bidder (1890), carmine particles seemed to have no effect whatever on the dermal pores, but were swept into the interior of the sponge with
Size: 2946px × 1696px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookpublisherphiladelphialondonjblipp, booksubjectnervoussystem
