No. 2.] MORPHOLOGY OF THE ACTINOZOA. I43 



coiled thread, similar to those originally described by Haime. 

 They are especially abundant in the upper part of the column, 

 and occur throughout the entire thickness of the epithelial 

 layer down to the nerve layer. In the lower part of the epi- 

 thelium, however, they are principally represented by highly 

 refractive globules of various sizes, some perfectly homogeneous, 

 others split with irregular portions of various sizes ; these 

 globules I judge to be developing nematocysts on account of 

 their behavior to various staining reagents, which is exactly 

 like that shown by the fully developed cysts. They have been 

 described and similarly identified by Jourdan. A second form 

 of nematocyst is also present, chiefly in the outer portions of 

 epithelium. It is much smaller than the large Cnidae glomi- 

 ferae (Gosse), and is cylindrical, measuring 28 /x. in length, and 

 5 /i in breadth. It is well differentiated by both gold and 

 saffranin staining, taking with the former a faint pinkish tinge, 

 and with the latter a bright orange. It is clear, the spiral 

 portion of the filament not being visible, while the " Axen- 

 korper" (Mobius) is very readily seen. A few nematocysts 

 resembling those found in the tentacles and disc also occur. 

 Undoubtedly too much stress has been laid upon slight dif- 

 ferences in shape, in distinguishing different forms of ne- 

 matocysts. Haime certainly erred in this respect, and von 

 Heider also, though to a less degree. The two forms described 

 by the latter from the tentacles differ only in size, and are 

 probably the same, and it does not appear to me to be neces- 

 sary to distinguish between the two forms of Cnidae glomiferas 

 he describes from the column wall. Probably the second form 

 I have described above is identical with von Heider's form d 

 from the column epithelium. 



The epithelium is covered on its free surface by a cuticle. 

 Gland cells are very abundant, and are of the same kinds as 

 were found on the disc. 



The nerve layer consists of a very strong band of fibres, 

 which lies immediately above the muscle band. It is traversed 

 at right angles by fine processes, both from the epithehal cells 

 and from the mesogloeal lamellae which support the muscle 

 fibres. A few nuclei are to be seen lying among the nerve 

 fibres, but they are very few and small, resembling those 

 found in the nerve layer of the disc. They are probably gan- 



