XX PROCEEDINGS OF THE 



ments, which now appear as spontaneously moving spherules. These 

 increase in size, develop on one end a cilia-wreath, within which a 

 mouth makes its appearance, and the free-swimming nucleus-fragment 

 becomes gradually changed into a form which entirely agrees with the 

 Trichodlna grandinella of Ehrenberg. 



These TrichodincB now multiply by fission, first developing a pos- 

 terior wreath of cilia, and then dividing transversely between the 

 anterior and posterior wreaths. After this each fixes itself by the 

 end on which the n)outh is situated, a short stem becomes here 

 developed, and the cilia-wreath gradually disappears. Then upon 

 the free end the peristome and cilia-disk make their appearance, and 

 the growth of the stem completes the development. 



Everts remarks that in this process we have au example of alter- 

 nation of generations. There is one point, however, in which he has 

 overlooked its essential difference from a true alternation of genera- 

 tions — namely, the absence of any intercalation of a proper sexual 

 reproduction. 



Ray Lankester* has subjected to spectrum-analysis the blue 

 colouring-matter of Stentor cceruleus. This occurs in the form 

 of minute granules in the cortical layer of the animal ; and Lankester 

 finds that it gives two strong absorption-bands of remarkable inten- 

 sity considering the small quantity of the matter which can be sub- 

 mitted to examination. He cannot identify these bands with those 

 of any other organic colouring-matter, and to the peculiar ])igment 

 in which he finds them, he gives the name stentorin. 



He has also examined the bright green colouring-matter o( Sientor 

 Miilleri, and finds that instead of giving the stentorin absorption- 

 bands it gives a single band like that of the chlorophylloid matter of 

 Hydra viridis and of Spongilla. 



Ray Lankester f also described, under the name of Toi'quatella 

 typica, a remarkable marine Infusorium, which, though quite desti- 

 tute of true cilia, can scarcely be separated from the proper Cililta. 

 With the general structure of the ciliate Infusoria, the place of a 

 peristomal cilia-wreath is taken by a singular plicated membrane 

 which forms a wide, frill-like, very mobile appendage surrounding 

 the oral end of the animal, and projecting to a considerable distance 

 beyond it. The author regards Toi'quatella typica as the type of a 

 distinct section of the Ciliata, to which he gives the name of 

 Calycata. 



Of all the authors who since Von Siebold have applied themselves 

 * Quart. Jouni. Micr. Sci. 1S73. t Ibid. 1874. 



