OP CILIATED INFUSORIA 247 



extremity only, as well as by the comparative absence of food 

 contents — so that the nucleus and the more developed buccal 

 cylinder are very plainly seen. In twenty-four hours or so the 

 appearance of the organism becomes distinctly altered, as may 

 be seen by the specimen shown in E ( x 375), in which short Cilia 

 had developed all round the body, and in which the larger amount 

 of contents hid the nucleus and in part also the buccal cyhnder. 

 Later on, when such organisms become fully developed, they 

 prove the most ravenous creatures, and may often be seen gorged 

 with food of different kinds — sometimes Diatoms, sometimes 

 Oscillatorias (which may be taken in so as greatly to distort 

 their bodies), and at other times with green algoid corpuscles, 

 such as may be seen in F under a lower degree of enlargement 

 (X 250). 



On other occasions I have seen Chilodons produced from 

 Euglenee by a very similar set of changes. Transformations of 

 this kind, as well as into other forms of Ciliates, or into Amcebse, 

 are prone to occur when portions of a fresh Euglena pellicle are 

 transferred to the surface of water in a stone pot, on which the 

 cover is subsequently placed. On examination of portions of this 

 pellicle after an interval of seven, ten, or more days, we may often 

 find transformations, of the kind indicated, occurring in some of 

 the EuglenjE which have thus been left not only cut off from all 

 rays of light, but in a very confined air space. 



(c) On the Segmentation of some Encysted Amoebae and 

 the Conversion of the Segments into Ciliated Infusoria. 



It has been known since the investigations of Spallanzani that 

 tufts of moss and lichen are tenanted by three kinds of organisms, 

 all of which have the power of reviving after even prolonged 

 periods of what appears to be complete dessication. The animals 

 recognised by him were certain Rotifers, a few Nematoids, and 

 some of the curious group of Tardigrades, to which Spallanzani 

 gave the name of 'Sloths.' When working at the 'Free 

 Nematoids' in 1864 I repeatedly found these same organisms 

 in moss and lichen from the most varied sites, and ascertained 

 that the Nematoids met with, in most cases, belonged to one or 

 other of two genera (Plectus and Aphelenchus), several species 

 of which were described in my " Monograph on the Anguillulidae 



