PIECE-MEAL REPRODUCTION. 145 



There is one circumstance, however, in connection with the 

 movements of dianthus which is of a very remarkable character, 

 and which conducts us to another branch of our subject, namely, 

 the reproduction of the Anemones. 



It frequently happens that, when a large specimen of dianthus 

 has been attached for any length of time to the same spot in 

 the Aquarium, on moving away it leaves small portions of its 

 extended base still adhering to the glass or stone, as though the 

 animal found it easier to tear its body asunder than to remove 

 these portions from the spot to which they had become so firmly 

 rooted. The fragments thus left behind soon contract, become 

 smooth, and spherical or oval in outline, and in the course of a 

 few weeks may be seen each with a well-developed disk sur- 

 rounded with tentacles, transformed, in fact, into perfect though 

 minute Anemones. Occasionally the larger portions which are 

 torn off from the base of the parent animal gradually separate 

 into two pieces, each of which in due time grows up to be a per- 

 fect dianthus. This mode of reproduction has been observed not 

 only in dianthus, but also, on rare occasions, in the beautiful 

 Segartia venusta, or Orange-disked Anemone. 



The process of reproduction by spontaneous division, of which 

 the above mode of increase is only a phase, obtains more or less 

 amongst all the Anemones. In most cases, however, the divi- 

 sion of the animal is into two parts only, and longitudinally from 

 above downwards ; the separation commencing at the margin of 

 the disk, and gradually extending across and down the column, 

 until the division is complete, when the two portions close, and 

 before long become perfect Anemones. 



We have oiirselves observed this phenomenon in AntJica cereus 

 though from the expedition with which the business was effected, 

 we missed the first stage of the actual process of separation. The 

 animal was attached to the perpendicular side of a tank, against 

 the light, and with its base towards us, so that we had a most 

 favourable opportunity of witnessing its procedure. Not an hour 

 before the separation of the two portions was nearly completed, 

 the only indication to be seen of the approaching change was an 

 unusual lateral elongation and flattening of the body, the tentacles 

 along the two straightened sides being curled in and bent down 

 to the glass, while the base showed a divergence of the dark con- 

 tents of the internal cavity towards the two extremes of ths 







