412 H. W. KING ON AMOEBA, 



or sedimentary matter that induced their search for many hours 

 and often days, and then as the environment of the beings becomes 

 abnormal, like a fly caged in a glass box, they will slowly show 

 signs of decreasing and unnatural action, as if a comatose condition 

 was passing over them, and finally they assume an encysted state, 

 when all co-ordinate vital action is suspended. Should a fresh 

 supply of the native water they were living in be added, they regain 

 their normal condition, and move and glide restimulated to 

 natural life. 



A most interesting form of these organisms of a low type of 

 development compared with Amceba radiosa or A. prmce^^s, which I 

 propose naming Am<ieha endo-divisa (Fig. 1, PI. XIX.), was living 

 in the dipping from Colon. It was of a very pale straw colour, of 

 a film-like nature, and nearly transparent. It had an almost 

 perfect pear-shaped outline, which was its normal form when not 

 exteriorly influenced, but when passing among small particles of 

 matter in the water it would contract in order to pass between the 

 obstructions. When it freed itself it would expand to its normal 

 form, and continue gliding as if searching among the matter there 

 for food, evidently showing selective attributes as other low 

 Protozoa will do. Some — " like the malarial — live in the plasma 

 on led-blood corpuscles ; there are other Protozoa that infest the 

 tissues of the body, some preferring the muscles, some the connec- 

 tive tissue, others again the nervous system" ("Brit. Med. 

 Journ.," Vol. ii., p. 825, 1893). Sometimes a portion of the 

 almost transparent ectosarc of tliis Amoeba would be protruded 

 and retracted again, and then another process would be extended 

 in a different direction, in a manner common to such attributes in 

 Amoebae. The extension, and retraction of the ectosarc goes on 

 simultaneously with the motion of the Amoeba, and several difi'erent 

 impulses may influence the organism at the same time. One 

 impels it to travel, another to select, and another to attach itself, 

 while other impulses influence circulation and minor internal move- 

 ments. Whatever motion the ectosarc may take, and however 

 contracted the being becomes, it always returns to its normal out- 

 line. A peculiarity of the structure of this Amoeba is that the 

 endosarc does not assume a diffused arrangement, but from a small 

 spheroidal mass at the narrow end of the Amceba the endosarc is 

 elongated into several finger-like rays, extending nearly the whole 

 length of the animal. These rays of the endosarc when compressed 



