644 RECORD OF CURRENT RESEARCHES RELATING TO 



movement. On this, small pieces were cut off from different parts of 

 the body ; at first without movement, in two hours after they were 

 quite active. In the second area, exhibitions of movement were very 

 common. In the third, all the parts and pieces were quite active. 

 In the median portion the ctenophores of one row exhibited a contrary 

 direction to the rest. These experiments conclusively demonstrate 

 that parts disconnected from the anal area are capable of independent 

 movement. 



Experiment B. — A row of ctenophoral plates was separated by 

 incision, and a division transverse to its long axis at a distance of 

 about 2 centimetres from the anal pole was made ; for a moment the 

 movements of all the ctenophores ceased ; then the uninjured plates 

 began to move, then the distal portion, and last of all the proximal 

 (oral) portion of the injured plate exhibited activity. In the last 

 two the movements were independent of one another. These experi- 

 ments throw into marked relief the extraordinary capacity which the 

 different parts of the injured Beroe have of performing separate move- 

 ments, just as though they were distinct animals. 



The author further found that the movement of the injured animals 

 was in the same direction as that of the uninjured, and that the same 

 power of direction was possessed by them after and before the experi- 

 ment. 



Looked at generally, tliese remarkable observations afford con- 

 clusive support to the doctrine that the " central region " at the apical 

 pole is not really the centre of the nervous energy of the animal, 

 while they show that nerve-cells are at any rate scattered over the 

 whole of the body, however more numerous they may be in one region, 

 and, moreover, these nerve-cells may be functional centres for any given 

 part of the body. The facts here detailed are completely paralleled 

 by the results already obtained from the study of the Medusfe, and we 

 may safely assert that " a distinctly localized central nervous system is 

 not present inBeroe; its central cells are distributed over the whole body 

 and are only more closely aggregated in the region of the anal pole." 



Pleurobrachia pileus.* — In a few notes on this animal, no 

 specimen of which was found in a sexually mature condition, Herr 

 Hartmann points out the presence on t^vo lobes of two roimd, red, 

 granular pigment-spots ; these, which it is possible were rudimentary 

 eyes, are not to be confounded with the ctenocyst, or auditory vesicle. 

 The oesophagus-like portion of the digestive canal was connected with 

 the stomach and the funnel by an orifice surrounded by a circular 

 projection, and provided with circular and longitudinal muscles. At 

 the oral pole he detected ganglia which gave off nerve-filaments to the 

 ctenophoral plates, and to the parenchyma of the body, and which 

 were further connected with one another by transverse commissures. 

 The branches of the tentacles were beset with a number of rounded 

 tubercles, between which there was diffused, in the primary portions 

 of the tentacle, a reddish pigment ; these tubercles were provided 

 with a number of urticating capsules. 



* 'SB. Gcs. niiturf. Fromi.l. B.rlin,' 1S79, p. 25. 



