OF CILIATED INFUSORIA 251 



all the great encysted Amoebae, with a large quantity of adherent 

 foreign particles. 



These red Ciliates, in their immature condition, as found within 

 the cysts, are slightly pointed at the anterior extremity, where 

 short ciUa are principally developed. Their bodies have been so 

 closely packed with red corpuscles^ that I have hitherto quite 

 failed to make out the shape and situation of their mouth ; and I 

 have been unable to preserve them long enough in their free state 

 beneath the cover-glass to allow these corpuscles to disappear. 

 They doubtless would disappear in the course of a day or two, 

 just as the very similar corpuscles found in the bodies of immature 

 Glaucomas, derived from the eggs of certain Rotifers belonging to 

 the genus Callidina, have been seen to disappear during the time 

 needful for the attainment of their adult form, as I have elsewhere 

 described.^ 



We have here, then, another very important mode of origin of 

 Ciliates, of a kind not previously suspected. The orange-red 

 colour, more or less marked, of the Amoeba in its free and in its 

 encysted state ; the character of its cyst ; the finding within such 

 a cyst a number of motionless but unequal red spheres, into which 

 the encysted mass had separated ; and within others the existence 

 of a number of similarly unequal, active, red Ciliates, constitute a 

 set of facts which can only admit of one interpretation. It 

 seems clear that the red Ciliates have been developed from the 

 red Amoebae, after they had become encysted and had undergone 

 segmentation — under the influence of the unnatural conditions to 

 which they were exposed during the soaking of the lichen for 

 many days in distilled water. 



(d) On the Transformation of the Substance of the Eggs 

 of a Tardigrade into Ciliated Infusoria. 



The Tardigrades, on which the following observations have been 

 made, have all belonged to the genus Macrobiotus, and on reference 

 to the plates and descriptions given by Doyere in his celebrated 

 " Memoire sur les Tardigrades " 3 it is clear that they have all 

 been specimens of M. Oberhauser. These curious creatures were 

 first observed and described by Eichhorn in 1767, and named by 



' The mode of formation of which is referred to on p. 268. 



= "Studies in Heterogenesis," pp. iig-124. 



3 " Ann. des Sciences Naturelles " (Zool.), 1840, p. 269. 



