352 W. ARCHER. 



very fine filament, of equable but hardly definable diameter, 

 and considerable refractive power. It proceeds from the 

 cortical layer without any basal expansion ; it is not dimi- 

 nished at its apex, but ends as if abruptly cut off". In the 

 ordinary progressing condition of the sarcodine, it appears 

 precisely at the anterior extremity, and fully extended, 

 though, as will be understood, that on certain alterations 

 of form and figure of the body-mass ensuing, it is some- 

 times withdrawn from observation. When in full view it 

 is carried like that of a Euglena, extended and tentatively 

 waved about. It is sometimes spirally curved, the coils 

 running along it like advancing waves. These movements 

 may be arrested, the flagellum remaining in the same position 

 for a considerable time, as if wearied. The author never saw 

 any retraction of it, or division or branching, or any current 

 of granules in it — or, in short, he did not observe any ten- 

 dency to evince " pseudopodial " characteristics. 



Another peculiarity of this curious form is its surface 

 being covered over with minute bacillar bodies, best com- 

 parable, as it were, to certain bacteria, and of greater refrin- 

 gent power than the cortical substance itself. These little 

 bodies ordinarily lie with their longitudinal axis parallel to 

 the superficies of the body, on which they appear coherent ; 

 they sometimes stand off" obliquely or vertically. Thus the 

 whole surface gains that rough appearance Avhich induced 

 the author to employ his specific name. Sometimes, when a 

 pseudopodium becomes considerably elongate, these bodies 

 become separated, and the upper part of a pseudopodium 

 may thus become almost or quite free from them and appear 

 smooth and clear. 



The author thinks it highly unlikely that this form could 

 be identical with Hertwig and Lesser's Dactylo splicer ium 

 vitreum, as the fringe of minute processes around that form 

 are quite different from the bacillar bodies here described. 

 Nay, Mastigamoeba itself gives off sometimes very minute, 

 thinly scattered, and slender but longer processes of similar 

 nature (comparable to those of Amoeba mllosa), from the 

 posterior pseudopodia. 



The outer border formed by the ectosarc averages in breadth 

 about 0005 millimetre. Besides the minute, strongly re- 

 fractive granules of varying size, characteristic of every 

 sarcodine, other larger globules (some 0"003 millimetre in 

 diameter and more) occur, partly colourless and then darkly 

 and sharply contoured, partly yellowish-red or reddish- 

 brown, imparting to the endosarc its orange-red aspect. 

 Near the limits between ecto- and endosarc, there occur in 



