210 NATURAL HISTORY SOCIETY OF DUBLIN. 



able to move about for some days, but never with activity. They seemed, 

 however, to have quite closed up their wounds. I could not examine 

 them anatomically, as they were so softened before I removed them 

 from the vessel that dissection was impossible. "When removing 

 them, I looked for the others of the same species which I put into the 

 vessel, and I found that these had also tried to divide, and apparently 

 in the same way, from the base upwards. 



The observation goes far enough, however, to prove that division 

 was completed, and that the two halves lived as independent animals 

 for a few days. The whole time which the division took, from the first 

 observation of the opening in the base to the complete separation of the 

 halves, was barely three hours. The exciting cause of the process seems 

 to have been the condition of the water in the vessel, just verging on 

 decomposition. The most important part of the observation is the mode 

 of the division. 



Before discussing this, I will quote the only case which I have been 

 able to find recorded of a similar kind. Gosse, in his work entitled 

 " Tenby," speaking of the rarity of the occurrence of fissiparous gene- 

 ration in Actinaria, states that he had never seen it occur spontaneously 

 himself, but quotes the following observation of a friend : — " An Anthea 

 cereus, which had been in captivity thirteen days, devoured with great 

 relish a dead shellfish. I watched the operation of seizing and swallow- 

 ing, and there was nothing remarkable in the appearance of the Anthea 

 on Monday. On Tuesday morning, going to look at my prisoner, I ob- 

 served the rejected shell at the bottom of the jar ; and to my great puzzle- 

 ment, instead of one Anthea, there were two, of nearly equal size, but 

 smaller than my old friend. Both appeared languid, and, from the 

 margin of one, two tentacula appeared sprouting ; they hung in so very 

 flaccid a state, that I could not examine the mouth yesterday, but to-day 

 one exposes a mouth fully formed.'' We have little else recorded here 

 than the fact of the division and its extreme rapidity. There can be 

 little doubt that in this case, as in mine, the division was effected by 

 muscular action. 



Nearly a century ago Decquemare observed that several Actiniae 

 could be divided artificially in almost any way, the several parts being 

 capable of forming independent animals. Sir J. Dalyell has recorded a 

 mode of reproduction in one species — Actinia lacerata — accomplished to 

 some extent, apparently in the same way, by muscular action, as in 

 the case I have described. He describes, in this species, tbe outline of 

 the base becoming sinuous, and the prominences gradually, in the course 

 of a week or two, becoming pinched off, maintaining their connexion 

 only by a very slender lengthened filament, not in contact with the 

 glass, but free above it. Rupture of the connecting thread at length 

 takes place, and the independent fragment becomes developed into a 

 perfect anemone. He says of the process : — ' ' It is not quite obvious how 

 the prolongation is effected, unless by contraction of the basis, and reces- 

 sion of the fragment from the point it originally occupied. All authorities 



