PHYSALIA 95 



succeeded in pressing the air out of the aperture. However, a yoiuig Phi/salla of five lines in 

 length possessed this power : after I had touched the animal a few times, it suddenly expelled 

 all the air from its bladder, and sank to the bottom of the glass. 



" Besides the prehensile filaments and suckers, we find between these organs, on the 

 under surface of the bladdei", one or many bundles of short threads, which may he regarded 

 as young. Different parts are distinguishable in these bundles, namely, a long thread closed 

 at its apex ; then a tubular or funnel-shaped body ; and a small globe at the root of the two 

 preceding. These parts of the bundle were easily detached when the animal was touched, 

 which clearly showed them to be young, as this phenomenon is observed in all the lower 

 animals. Of the three organs here mentioned I hold the first, the long thread, to be the 

 receptacle of fluid of an undeveloped prehensile thread, the funnel-shaped body for a sucker, 

 and the small globe for the vesicular body, which is not yet filled with air. So that these 

 three parts form together the most essential parts of the body of the Pki/salia." 



De Blainville ('Manuel,' p. 113) has fallen into the most marvellous errors respecting 

 Phjsalia. Not content with discovering its mouth and an anus, he attributes to the Phi/salia 

 a stomach (the air-bladder), a foot (the crest), branchiae (the tentacles), and generative 

 apertures, besides a hepatic plate, vessels, and a central circulatory organ ! No wonder, then, 

 that he places PlnjsaUa among the Molluscs. 



Von Olfers, the author of the next essay of importance on the structure of the PJii/salia,^ 

 has not added very much to w'hat was made known by Eschscholz. 



He describes the chambered structure of the crest, and mentions the sphincter of 

 the aperture, but he affirms that a probe introduced into the latter leads into the space 

 between the outer bladder and the inner, in which last he was unable to detect any opening. 

 Like Eichwald he ascribes to the inner, air-containing, bladder csecal processes, which lie 

 in the compartments of the crest. 



Von Olfers further mentions the villi of the polypites (or large and small suckers), 

 and the communication of the cavity of the latter with the cavity which lies between 

 the external vesicle, or body-wall, and the internal proper air-bladder. Less accurate in some 

 respects than his predecessor, he affirms the tentacular receptacles to have an aperture at 

 their apex, though he admits he has never seen the supposed mouths in a state of dila- 

 tation. 



The thread-cells, while in situ in the vilh and tentacles, are described as small, round 

 glands ; while, when partially detached and adherent by their thread only, to the latter. 

 Von Olfers has mistaken them for Vorticellm. 



The supposed budding young, or " brut," of Eschscholz, are called " keimbiindel" — 

 germ-bundles, and are carefully analysed by Von Olfers into bodies of three kinds : L Small 

 suckers, similar to the large ones, but smaller ; 2. Club-shaped bodies ; 3. Ovate or 

 pyriform bodies. 



Von Olfers states particularly that he does not consider these to be reproductive organs 

 (I. c, p. 163), nor does he agree in Eschscholz's view of their nature; but he imagines that 

 the ovate or pyriform bodies are " the germs of young Phymlia, which, probably, become 



^ 'Ueber die grosse Seeblase (P^ysa/ia arethma) und die Gattung der Seeblaseu im Allgeraeinen.' 

 Abhandlungen der Kon. Akademie d. Wissenschaften zu Berlin, 1831. 



