186 Transmuiatioii of Form in certain Protozoa. 



Fig. 14 is an interesting form, as exhibiting a stage of progress 

 towards Pbilodina. 



Fig. 16 is a Paramoecinm, or Loxodes, in wbicli the rudiment 

 of the tail-foot is very evident by reflexion of hght, while 



Fig. 15 shows the tail-foot more fully developed. 



Fig. 17 is a globular form of Pbilodina, with the telescopic tail 

 just making its appearance. All these forms I have repeatedly 

 verified as transitional, having seen them evolve into Calhdina, 

 Pbilodina, Kotifer, or in the other direction to Amceba, &c. 



Fig. 18 is simply inserted as a beautiful globular Infusorium, 

 whose whole surface is covered with cilia, which work in regular 

 order, so as to revolve itself slowly and gracefully over the field. 

 It is here magnified, as are all the other specimens, by 250 to 300 x * 



Fig. 20 is an elementary, probably early, stage of Pbilodina, 

 the tail-foot being very distinct. 



Fig. 19 is a still more developed form of the same Infusorium. 



Fig. 21 is possibly Enteroplea hydatina, found among a num- 

 ber of Philodinaea in water containing Yalisneria, sent from Liver- 

 pool by Mr. Chautrell. 



Figs. 22 and 23 are forms of Pbilodina modified by opium. 



Figs. 24 and 25 are the fully-developed forms which I am 

 accustomed to find in water containing vegetable growths. I shall 

 have to refer to them at greater length when speaking of the dis- 

 tinction without a difference which seems to me to have been made 

 by classifiers. 



Fig. 26 is another form of Pbilodina which I frequently find 

 the Calhdina assuming in its changes. 



Fig. 27 is a perspective view of a Callidina, with the proboscis 

 in the centre. 



Fig. 28 is another form, intermediate between Carchesium and 

 Callidina. 



Figs. 29a and h are some rudimentary forms of Infusorium, pos- 

 sibly passing to Floscularia in water containing Sphagnum palustre. 



I have no further history of this Infusorium. 



Before proceeding to the general remarks, I wiU ofier a few 

 observations on the subject of the Plate. 



In the first place, it has long been my opinion that Actinophrijs 

 Sol is only a phase of the life-history of Amoeba, 



It will be observed that Mr. Chantrell speaks of the form of 

 Infusorium found in his researches, as varying at different times 

 between Amoeba and other forms. I have often referred to the 

 change from Globular to Amoeba.f 



* If anv of Tour readers will kindly name it for mc, either by letter or through 

 'M. M. J.,' I shall feel obliged. 



t See 'M. M. J.,' Aug., 1869, \x 104, line 2; May, 1871, p. 255, lines 16, 17, 

 and 18. 



