OF CILIATED INFUSORIA 243 



turbid than the first (then ten days old), and the scum on its surface was thicker, 

 more coherent, and found to contain, in addition to many different kinds of 

 Bacteria, a multitude of minute Zooglcea masses in a very early stage. When 

 examined again on the sixth day, the trurbidity was more marked and the 

 pellicle was thicker ; and the first portion examined microscopically was 

 found to be swarming with Zooglcea masses segmenting into Monads, 

 together with discrete corpuscles and multitudes of active Monads. There 

 were swarms, also, of the primary Ciliate matrices in the pellicle, together 

 with large numbers of free and active Kolpodse. But examination of the scum 

 made from the fresh grass, on this fourteenth day showed it to be still very 

 thin, and composed only of Bacteria. No single Zooglcea mass. Monad or 

 Ciliate, was seen in the portions of this pellicle that were examined. 



The conclusions to which the evidence compels us to arrive 

 seem almost incredible. It was amazing enough to find aggre- 

 gates of Bacteria fusing and undergoing molecular changes, as a 

 result of which now Monads, now Amoebae, now Fungus-germs 

 appear as ultimate products ; but when we find larger masses of 

 Bacteria individualising themselves and going through a series 

 of inscrutable changes till revolving Ciliated embryos are pro- 

 duced, which speedily rupture their cysts and appear as active 

 free-swimming animalcules, there is room for still greater amaze- 

 ment. Still the evidence seems absolutely conclusive ; and in face 

 of it our preconceptions must give way. 



We are likewise unable to account, by means of known facts, for 

 the late secondary brood of Ciliates that has been traced as begin- 

 ning in minute particles which gradually increase in size, and 

 ultimately produce very similar encysted matrices, from which 

 Cihates are born. Existing knowledge can give no explanation 

 of the origin of such bodies. Are the particles from which they 

 proceed minute germs of Ciliates ? Science knows nothing of 

 such germs. Are the particles then only another primordial form 

 of life, having the potentiality of unfolding, as they grow, into 

 Ciliated Infusoria ? This seems incredible : yet if they are not 

 unknown germs, they must be new-born particles. 



(b) On the Transformation of Encysted Euglenae into 

 Ciliated Infusoria. 



Many different forms of Ciliates are at times produced by the 

 transformation of encysted Euglenae kept under unnatura condi- 

 tions. When, for instance, a gathering of Euglenas is put into a 

 rather shallow vessel of water and left exposed to light and air 



