— 48 — 



ferent intensity of the stain, it l)econies thickened from its 

 free border to the l)ase. In most cases this intensification of 

 the dye of the nieml)raiie is very gradual, its free border 

 being slightly grayish (along it rnns the dark border flagel- 

 lum); further, towards the base, the membrane becomes 

 bluish-black (after being stained with Heidenhain's haema- 

 toxylin), and the base itself seems absolutely black and not 

 transparent. It is more seldom to distinguish in the membrane 

 2 sharply limited zones: a darker basal zone, and a lighter, 

 distal. At any rate, I did not succeed in observing a distinctly 

 differentiated «chomatic basis>, according to Dob ell's termi- 

 nology. Altogether, the question of a «chromatic basis> requi- 

 res to be cleared further. The «chromatic basis> presents an 

 arcuate formation, srongiy stainable with haematoxylin, situated 

 at the base of the membrane in Trichomonas. Most of the aut- 

 hors restrict themselves to the description of this organ and only 

 Kucinsky (26) stops to .examine the question of the physiolo- 

 gical and morphological significance of the chromatic basis in his 

 large work on Trichomonads. Kucinsky supposes that the basis 

 together with the axostyle presents a system of fibrils joined 

 in the blepharoplast and serving as a support for the free 

 flagella of the animal. As far as 1 can judge from his rather 

 confused account, Kucinsky denies the close connection 

 between the chromatic basis and the membrane. Kuc in sky's 

 conviction of the independence of both named formations is 

 chiefly upheld l)y such forms as Trichomonas gaUinaram and 

 Protrichomonas legeri in wliich together witli a total absence 

 of a membrane the chromatic basis is present. 1 consider 

 K'ucinsky's views to be founded on insufficient proofs. Firstly, 

 the study of the literature points to a very close morphologi- 

 cal connection between tlie basis and the membrane. The 

 chromatic basis has the same curved ^aicuate shape as the 

 membrane, and always lies at the base of the latter. Further, 

 the chromatic basis of Protrichomonas is arbitrarily taken for 

 such by Kucinsky, as Allxeieff (3) Avho has described the 

 given Mastigophora, compares the chromatic filament found 

 by him in Protrichomonas with the axostyle of Trichomonads, 

 and not with the chromatic basis. 



And lastly, observations on such large objects, as Giganto- 

 monas have brought me to the conclusion that the chromatic 

 basis, as a distinct, independent formation, does not exist at 



