250 HETEROGENETIC ORIGIN 



out coarsely-lobate projections as in Fig. 54, A (x 150). These 

 projections are generally perfectly hyaline and translucent, con- 

 trasting notably with the blood-red colour of the great bulk of the 

 organism. Sometimes large quantities of undigested refuse, in the 

 form of spherical pellets of different sizes, are extruded, and the 

 Amoeba may begin to encyst itself at once, as in the paler red 

 specimen represented in B (x 200). The movements of these 

 creatures are so extremely sluggish that I was able to take the 

 foregoing photographs while they were still living. 



These Amcebse are not always of a pale red or dark red colour ; 

 some are nearly colourless. Such variations depend upon the 

 portions of the lichen upon which they have been feeding — some 

 of the under surface being whitish, while other parts are of a red- 

 brown colour. The undigested refuse pellets may be all extruded 

 before, or not till after, the Amcebas have begun to encyst them- 

 selves. The cyst itself is extremely thin and apparently somewhat 

 glutinous, as particles of different kinds and some of the small 

 refuse pellets are generally found adhering to its outer surface, as 

 in Fig. 54, B. In this specimen digestion had only been partially 

 accomplished, as there were food-masses still within, as well as 

 outside, the pale red body-substance. 



One of these pale red encysted Amoebae was found which had 

 divided into eight or ten unequal spherical segments, such as 

 may be seen in C ( x 200). Only five segments are distinctly to 

 be made out in the photograph, but under examination by the 

 microscope others were seen at lower levels. They were all 

 motionless, granular masses of protoplasm — probably about to be 

 evolved into Ciliates, seeing that such bodies densely packed with 

 large pale red corpuscles and granules were seen actively swarming 

 about within other of these Amoeba cysts. One of them contain- 

 ing six dark red and very active Ciliates is shown in D ( X 200), 

 after the movements of the Ciliates had been brought to rest by 

 means of a weak osmic acid solution. Both of these cysts had an 

 abundance of the usual minute particles adhering to their outer 

 surface. Another rather larger cyst, containing six very active, 

 blood-red Ciliates, is shown in E (x 200). This cyst is seemingly 

 dilated by the active movements of the Ciliates, some of which had 

 probably escaped through a small opening below, where the thin 

 membrane can be seen to be bulged. Other similar specimens 

 have also been found containing the same kind of Cihates, more 

 or less red, and the flexible cysts were coated externally, as were 



