ANATOMY OF LIMNOCNIDA TANGANYICA. 277 
organ are multinucleate and, in some regions, vacuolated. 
Moreover, spaces may occur in this hypertrophied mass of cells 
within which one or more of the cells may be floating. Similar 
cells (fig. 7) occur in the lumen of the circular canal and in 
the radial canals. In all, the nucleus is broken up into several 
pieces, and in many, vacuoles are present. 
The function of this extraordinary organ of the circular canal 
is extremely doubtful. Nor are there any means of settling the 
matter until living material can be obtained for examination. 
The abundant discharge of the cells which are found in the 
circular and radial canals, would indicate an excretory function 
by which noxious or useless matter is carried to the exterior. 
On the other hand, it is possible that the organ is endowed 
with the power of secreting some digestive ferment which is 
discharged into the circular canal and is thence conveyed into 
the shallow gastric cavity by the radial canals; or, again, the 
katalysis of the free cells themselves may supply a material of 
economic value to the organism. 
The endoderm lamella is situated very close to the sub- 
umbrellar ectoderm and is composed of a single layer of small 
cubical cells which increase in size and become vacuolated near 
the gastric cavity (fig. 6, end. /.). 
The tentacle axes are hollow and composed of large, clear, 
thin-walled cells, each with a small nucleus on one side. The 
cell contents seem to be almost entirely fluid or gelatinous, and 
hardly any trace of granular protoplasm can be made out. It 
is probable that the turgidity of these cells may be the cause 
of the rigidity of the tentacles. The lumen of the tentacle is 
continuous with that of the circular canal, as seen in the 
section figured in fig. 6, which passes through the base of one 
of the radial tentacles. 
c. REPRODUCTION BY BUDDING. 
In certain of the individuals examined, the external wall of 
the manubrium was found to be covered with numerous small 
Medusa buds in yarious stages of development. The region 
