iç8 



DR. tWAJ] IKEDA. 



wards the hydranth-basis and thicker towards the bulbous end invested 

 with filaments. Its non-papillated and papillatcd parts are externally 

 sharply demarkated from each other by the characteristic colored 

 ring. A close examination reveals the fact that the boundary corres- 

 ponds with the lower end of the perisarc, which is found in the papil- 

 latcd region. The relative lengths of the two regions vary a great deal 

 with the state of contraction of the parts ; when fully extended, the 

 non-papillated region makes up nearly one-third the length of the 

 entire hydrocaulus. The ten longitudinal canals are seen through the 

 integument. Anastomosis between these canals is not so frequent as 

 in C. nutans, C . pendula or C. nana ; it occurs in the non-papillated 

 region at four or five places at most, and most frequently near its 

 lower end. The papillae are arranged nearly in the same way as in 

 other known forms, forming, as they do, two apparently alternating 

 longitudinal rows along each canal. Their number and the mode of 

 distribution vary considerably with different individuals ; generally 

 speaking, they are most thickly and regularly distributed in the middle 

 part of the papillated region, though in many individuals they may be 

 found uniformly over the greater part of the papillated region. The 

 papillae become gradually larger and taller downwards, and finally 

 at the cuticular bulb they take the form of moderately long threads 

 ending with a small swelling. 



As to the internal anatomy of the hydrocaulus, there is little to 

 be added to the observations of previous writers. The ten longitudi- 

 nal canals coalesce anteriorly into a common cavity, the central space 

 of which is occupied by a parenchymatous mass. The outer endoder- 

 mal wall of the longitudinal canal consists of a single layer of con- 

 spicuously tall epithelial cells, while all the remaining parts consist 

 of the parenchyme. It is to be noted that the epithelial cells contain 

 numerous spherical granules which are uniformly scattered throughout 

 the finely granular cytoplasm. 



It need scarcely be mentioned that the papilla: consist of 



