KOFOID AND SWEZY: UNARMORED DINOFLAGELLATA 35 



developmeut, the "enidogene" (fig. G, 6), he states, however, that the number is 

 constant and equal to the number of zooids of the body, and also that they are 

 metamerically arranged. Thus he figures (191 Or, pi. 9, fig. 1) an individual of 

 eight zooids, each one of which contains a single "enidogene," centi*ally located 

 and oriented at an angle of alxiut 45° from the longitudinal. The excess of 

 cnidoplasts formed are ejected from the bod}^ or dissolution takes place in sihi. 



This metamerism of the nematocysts is not shown in our own material nor 

 in the figures of other investigators, including Chatton's figures of the mature 

 organelles. Its existence is thus apparently limited to this single stage of its 

 development. 



It is thus seen that the exact origin of these structures still remains a doubt- 

 ful point, as does also their fate after the completion of the development of a 

 new set of organelles in the body. Chatton has suggested that the old nemato- 

 cysts are dissolved in the cytoplasm, and in proof of this figures a colored re- 

 fractive body frequently seen by him in Polykrikos (1910c, fig. 15, pi. 9). A 

 comparison of his figure with some of the cell inclusions in other species of 

 the Gymnodinioidae as shown in our own material (pi. 4, fig. 46; pi. 5, fig. 52) 

 shows that a closely similar structure is frequently present in other forms where 

 nematocysts do not occur, and lessens the probability of this being a disinte- 

 grative phase of these organelles. 



