Miscellaneous. 447 



Gegenbaur, who describes them in Nausithoc and Chanjbdea as 

 hollow filaments standing in connexion with the cavity of the stomach, 

 regards them as reservoirs of the fluids moving in the gastro-vascular 

 system. Milne-Edwards indicates them as biliary canals in Charyhdea, 

 Leuckart compares them with the mesenterial filaments of the Actiniae, 

 indicated by him as kidney-like secretory organs. In all cases, how- 

 ever, they seem to have been regarded as hollow, and as opening freely 

 from the gastro-vascular system, outwardly or into the several cavities. 



The author had the opportunity of observing these filaments in 

 two species of Tamoya, in a Rhizostoma, and in a large Chrysaora. 

 In Tamoya the generative organs are situated in the wide lateral 

 pouches of the stomach, at a distance from the group of stomachal 

 filaments, which are visible to the naked eye as opake streaks in the 

 membrane of the stomach ; in this case, therefore, we cannot suppose 

 that there is any close relation between the organs. In all four spe- 

 cies the filaments are solid, and directed into the cavity of the sto- 

 mach : the latter fact is especially easy of proof in Chrysaora, in 

 which the filaments attain a length of several inches ; the former is 

 rendered particularly distinct by treatment with solution of chromic 

 acid, when the cortical layer may easily be brushed off from the solid 

 central cord, which is transparent, and, in fresh filaments, certainly 

 appears like a cavity. This renders Gegenbaur' s explanation im- 

 possible as regards the species observed by the author. 



It appeared to him more probable that the stomachal filaments 

 were connected with digestion. To confirm or contradict this sup- 

 position, he removed the groups of filaments from a living Tamoya 

 hoplonema, laid them on some muscles from the claw of a Crab and 

 a fragment of the posterior part of an Alpheus, and poured over them 

 a little sea- water. Corresponding pieces were laid in pure sea-water. 

 The latter had undergone no perceptible change in ten or twelve 

 hours ; but of the flesh under the influence of the stomachal filaments, 

 that of the Alpheus was completely, and that of the Crab almost 

 completely, dissolved to form a turbid fluid : the blackish-green shell 

 of the Alpheus had become reddish ; a slimy residue on the chitinous 

 plate, from which the muscles of the Crab's claw arise, still exhibited 

 its muscular nature under the microscope. The filaments still con- 

 tinued fresh, their cilia were vibrating, and they showed the ordinary 

 slow vermiform movement. 



The author considers it more probable that the filaments produce 

 a peculiar secretion different from that of the rest of the stomach, 

 than that they serve merely to increase the digestive surface of the 

 stomach, as he found on the surface of the filaments and in the 

 surrounding fluid, in Tamoya, irregular roundish corpuscles, of 

 001 mill, in diameter, with dark outlines, which did not occur in 

 the other parts of the stomach. 



Tlie occurrence of urticating organs in these filaments is very re- 

 markable. In Tamoya, Chryisaora, &c., they may perhaps serve for 

 the destruction of living prey ; but what is their office in the central 

 cavity of the polystomatous Rhizostoniidse, which is far removed 

 from the orifices of the anus ? — Siebold und K'Olliliers ZeifscJir'tft, 

 Dec. 20, 1858, p. 542. 



