December 2, 1898.] 



SCIENCE. 



779 



3. " In the movements of Ouramceha the 

 ■caudal filaments were entirely passive."* 



4. " When first seen I regarded the ani- 

 mal as an Amceba proteus dragging after it a 

 bundle of mycelial threads [accidentally 

 attached to it?]. * * * I came to the con- 

 clusion that the threads were parts of its 

 structure. * * * The caudal filaments 

 present so much resemblance to the my- 

 celial threads of fungi that I have sus- 

 pected they may be of this nature, and 

 parasitic in character, due to the germina- 

 tion of spores which had been swallowed as 

 food. * * * There is, however, perhaps an 

 important objection to this view, and that 

 is, the caudal filaments do not grow from a 

 mycelium within the protoplasmic mass of 

 the body of the animal. According to Mr. 

 Archer, Ouramceba * * * may be only a 

 varietal form of what I have considered to 

 be Amceha pi-oteus, but the solution of the 

 •question remains for future investigation. "f 



The next published allusion to this 

 problematic creature was in 1885. J Dr. 

 Oruber, in the description of his spe- 

 -cies Amaba binucleata, speaks of fungus fila- 

 ments lying within the body, but which, 

 in a chromic-acid preparation, issued in 

 tufts and in some places covered the ex- 

 terior. Confessing that he cannot explain 

 this singular effect of the acid, he suggests 

 that the coming-out of such fungus threads 

 in the living animal might produce appear- 

 ances like those figured by Leidy, and that 

 the strange attachments to Leidy's Oura- 

 mceba are nothing but such fungi. 



My own study of it began February 6, 

 1894. The specimen was taken three days 

 before at Wake Forest, in a small stream but 

 a few yards out of a spring. The current 

 was checked by a luxuriant growth of a 

 pond-weed here and there, so that a large 



* Fresh- Water Rhiz. N. Amer., p. 69. 

 tidem, p. 69-70. 



t Gruber, Zeitschrift f. Wissenschaft. Zool., 41:210, 

 211. 



brown Oscillaria, which abounded in the 

 collection, had no trouble to keep its footing 

 and thrive. This first specimen I had 

 under observation from the 6th of February 

 to the 22d of March, though after the first 

 six days it was in the encysted condition 

 represented in Fig. 7. At no other season 

 of the year than February and March and 

 in no other locality have I met with speci- 

 mens. 



EXPLANATION OF PLATE. 



Fig. 1. Filament of Ouramaiba branched 

 near peripheral end. Free-hand, 



Fig. 2. Another mode of branching. Free- 

 hand. 



Fig. 3. Detached filament, sketched free- 

 hand as it lay free in the water a few 

 minutes after its separation. 



Fig. 4. Cluster of detached filaments. 

 Free-hand. 



Fig. 5. A filament of a detached and 

 somewhat disintegrated mass, showing con- 

 nection with the spore. 



Fig. 6. A cluster of filaments springing 

 from included spore whose wall is plainly 

 distinguishable. Somewhat diagrammatic. 



Fig. 7. Encysted Ouramceba: a, filament 

 still attached to the protoplasm, which is 

 contracted from cyst- wall; b, shed filament 

 in mass of debris, c, attached to cyst. Cam. 

 Inc. X 95. 



Figs. 8-10. The same cluster of filaments 

 in three successive stages of development, 

 the stage in Fig. 9 being one day older than 

 that of Fig. 8, and Fig. 10 two days later 

 than Fig. 9. a and b are the original 

 branches of the germ-tube; a', a", primary 

 and secondary branches of a; b' and b", 

 primary and secondary branches of b ; c. v., 

 contractile vacuole. After tracings of Mr. 

 Martin F. Woodiuard^s camera lucida draw- 

 ings. X SOO. 



Fig. 11. Portion of a large specimen, 

 showing attachment of three clusters of 

 filaments. After Mr. Martin F. Woodward. 

 X 800. 



