Transmutation of Form in certain Protozoa. 187 



April 22, 1871, I found Actinophrys Sol and Amoeba in the 

 same water in which Sphagnum palustre had been put. 



The observation recorded in the Plate (Figs. 1 to 7) was made 

 July 20th, 1871, and is interesting and important as having been 

 made, not by myself, but by a perfectly disinterested person, a friend 

 of mine, Mr. F. Housmann, who is a very accurate draughtsman, 

 but who, in consequence of his being deaf and dumb, and not a 

 microscoj)ist, is not in a position to have any preconceived views, 

 and was not aware of what my own were upon the subject. I 

 simply observed the Actinophrys Sol (from water sent me from 

 Liverpool containing Valisneria), and its first change to an Amoeba. 

 I then left my friend to make drawings of any changes he might 

 see. On my return home, he presented me with the piece of paper 

 which I herewith enclose,* on which were the drawings of changes 

 in the Amoeba until the water dried up. 



The information derived has two points of interest ; the first, 

 the probable identity of Actinophrys with Amoeba ; and second, the 

 association of Paramoecium with the other two forms of Infusorium. 



In Fig. 9 (which I watched passing to its present state of 

 protruded sarcode from a form similar to Fig. 8) will be observed 

 the two depressions a a, which give a resemblance to forms 52 

 and 53 in Plate LXXXV., May 1871, and which I am accustomed 

 to recognize as decidedly transitional forms of Callidina. 



In Fig. li) aa, similar depressions give rise to a central tongue- 

 like process in the middle. 



The white portion represents the protruded sarcode, which in 

 Fig. 11 presents such a close resemblance to an Amoeba. 



If we compare Fig. 14 with some of the figures in the former 

 Plate, LXXXV., we shall see reason to consider it a transitional 

 form, especially when associated with Fig. 16, which shows the 

 white spot which reflects the light, and is in all probability a 

 rudimentary tail-foot, especially when viewed in connection with 

 Fig. 15, in which it is more marked. 



Figs. 14 and 15 were drawn at the same sitting, March 29, 

 1871, from the same drop of water, which I had prepared by 

 inserting a handful of dead leaves, in December, 1870, into about a 

 pint of water in a glass beaker, in the light and air of my study. 



Figs. 19 and 20 are forms which I recognize daily as progres- 

 sive towards the more mature forms shown in 24 and 25. 



Fig. 21 is a developed form, which I do not doubt is traceable 

 in its origin to the same source as the rest. 



In Figs. 22 and 23 we have a strong resemblance in form to 

 Fig. 50, Plate LXXXV., which presented a very interesting phase 

 of change as a Vorticella. 



* Mr. Johnson sent us the piece of paper which contained drawings exactly 

 similar to those in the accompanying Plate. — Ed. ' M. M. J.' 



