284 



Mr, F. W. Putnam gave an account of some peculiarities 

 he had noticed in humble-bees. 



■was the first to detect the existence of these bodies ; but he mistook them for pecu- 

 liar forms of spermatozoa of Actinia cereus. Immediately after this, if not at the 

 same date, Ehrenberg {Ahhandl. Berlin Akad., 1835. Jahrg. [1837.] p. 147) recognizes 

 their true office, and describes them as the prehensile organs, " Fang Angeln," of Hy- 

 dra. Yet, in 1842 ( Wiegm. Archiv), we find him inclined to deny that they have the 

 ^</»£rw!(7 properties, such as Wagner attributes to those which he found in Pelagia noc- 

 tiluca. In 1841 ( Wiegm. Archiv, p. 38), Wagner describes the nettling organs, " Nes- 

 selorgane," of Pelagia noctiluca, and, although he detects the spirally- rolled thread 

 in the capsule, and says of the thread, " sometimes it appears as if it had a canal," 

 and figures it so in his Icones Zootomicce, 1841, PL 33, fig. ix., B, yet it was reserved 

 for Doyere, in tlie latter part of the next year (Vompte Rendu, Aout., 1842, p. 429. 

 " Note sur quelques points de 1' anatomie des Hydros d' eau douce"), to describe 

 the mechanism of the Cnidse, and the mode of evolution of the tliread, with such 

 completeness as to anticipate everything, in this regard, that has been published 

 since, up to the year 18G0, when 1 figured and briefly pointed out (in Agassiz's Contri- 

 butions, Vol. III., PI. XT.*, fig. 16'', Aurelia flavidula, and description of plate p. 17; 

 and PI. xi.o, fig. 6, Coryne mirabilis) an as yet undescribed relation of the thread 

 to the cell in which it is coiled up. As the brilliant discovery of Doyere has been 

 kept in comparative obscurity, at least in this country, I will quote from his paper 

 such passages as will make it clear that he deserves the credit which has been as- 

 sumed by those who liave merely repeated his observations. On page 4.'J0, Compte 

 liendu, he says, " Ainsi le spicule ou dard, figure dans 1' interieur du sac par 31. 

 Corda {calcarea sagitta, Corda), et represente saillant au dehors par 31. Ehrenberg, 

 dans sa planche, ii., flg. 7 b, n'est autre que 1' espece de calice basilaire a trois 

 point en etoile, des pretendus hamegons. I.e long filament grele qui part de ce ca- 

 lice etoile etait, avant 1' evolution, invagine en dedans de lui-mgme et du calice ou 

 spicule par un retournement en doigt de gant, et formait au fond du sac cette appa- 

 rence de coussin que M. Corda a, nomrae vesica patelliformis ; un examen atteutif 

 et d' excellents instruments font meme reconnaitre dans ce coussin sa composition 

 par un fll enroule en spirale." On page 431, he speaks of the evolution of the 

 thread of this, and another smaller nettling-cell, by ensheathing itself, " des corpus- 

 cules plus petits et surtout beaucoup plus etroits que les precedents, ovoides, a par- 

 ois ^paisse contenant a leur interieur un fil enroule en spirale, qui sort comme le 

 long filament des hamegons, en s'engainaut en dedans de lui-meme." All that I 

 have been able to add to this, although the subject h is been pursued with the ut- 

 most rigor, and with the best lenses to be had, is the description of the relation of 

 the coiled thread to that part of its base which projects straight into the cavity of 

 the cell. Perhaps the greatest importance that can be attached to this is that it is 

 the most difficult to make out. However, the discovery of this feature solves the 

 whole mechanism of the organ. Although I had, in 1860, figured and briefly indi- 

 cated (^^roms's Cow^rift. ut supra) this part of its structure, yet it was not until 

 the fourth volume of the Contributions appeared, in 18ii2, that I described it in full, 

 as I had seen it in various animals, viz., in the ephyra of " Aurelia flavidula," p. 

 44; the hydraform of ''Coryne mirabilis," p. 209; " Actinia marginata," p. 210; 

 and " Hydractinia polyclina," p. 237. At first sight, I might seem to be anticipated 

 in this by Gosse, in his Evenings loith the microscope, London, 1859, or in his 

 Actinologia Britannica, London, 1860, p. xxix. introduction, and PI. xi., fig. 6; 

 but, upon examination of his illustration, I find nothing to justify it; and, from his 

 description in connection with the figure, I would judge that the Cnidse had been 

 injured and distorted by pressure. However, I leave it to others to judge whether 

 Gosse's description is sufficient to clear up the subject in this regard. 



Among the Ctenophorae, the cnida are so numerous, and so closely packed to- 

 gether, as to form a uniform layer all over the surface of the tentacle totally outside 

 of the exterior wall. 



