48 
only a mutilated Bolina, and by which the great regenerating power 
of this Ctenophore was made evident, I determined to make some 
more definite experiments. On the 18th July, at 7 p. m., 4 spec- 
imens were treated in the following way: 
A. 24 mm. long. The apical organ extirpated. 
B. 22 mm. long. Divided longitudinally in two halves, after 
the transversal (tentacular) axis, each piece having thus one 
complete lobe. The statocyst was left, nearly untouched, 
in the one part. 
C. 16 mm. long. Divided longitudinally in two halves after 
the sagittal axis, each part having thus two half lobes. 
The statocyst was left, nearly untouched, in the one part. 
D. 20 mm. long. Divided transversally in two parts, the cut 
being laid just below the infundibulum. 
The operated animals were placed in large jars full of water; 
no aeration was used, but the water was changed some times. The 
regenerative process could not be followed in detail on account of 
my absence on an excursion from the 20th to the 22d and from 
the 26th to the 27th. During the latter excursion the weather 
was very hot, and on my return to the laboratory I found that 
the animals had suffered somewhat from the temperature in the 
jars having been rather too high. Still the results of my experi¬ 
ments were very satisfactory. 
A. The 19th, 5 pm. The wound healed; a distinet accumu- 
lation of cells at the place of the apical organ. The animal had 
apparently no inconvenionces at all of the lacking of the organ. 
On the 23d the statocyst was regenerated and the whole organ 
fully formed; only the exeretory vessels were scarcely as large 
as normally. The animal otherwise completely healthy and normal. 
On the 25th the specimen was in every respect completely restored. 
B. The 19th, 5 pm. The wound healed; both pieces quite 
vigorous. On the 23rd both pieces had begun to form irregular, 
branching vessels from the remnants of the infundibulum and along 
the pharynx. The piece without the statacyst did not appear to differ 
