DERIVED ORGANIZATION 115 



This substance, according to Kofoid, appears to form at the expense 

 of the nuclear chromatin and increases or decreases— that is, the 

 parabasal body becomes larger or smaller apparently in relation to 

 metabolic demands. When the parabasal body is poor in chromatin 

 the blepharoplast and nucleus may be rich and vice versa. "Our 

 data are too incomplete to give a clear picture of the process, but 

 as far as they go they suggest the origin of the parabasal at the 

 expense of the chromatin of the nucleus, the movement of stain- 

 able substance on the rhizoplast, either to or from the blepharoplast 

 at the base of the flagella, and the wax and wane of the parabasal" 

 (Kofoid, 1916, p. 5). This interpretation is strengthened by the 

 positive reaction of the parabasal of some species to the Feulgen 

 nucleal test (see p. 57). 



Kofoid's interesting and suggestive interpretation of the nature 

 of the parabasal is very well sustained by the morphological rela- 

 tions of blepharoplast, nucleus and parabasal body in widely diverg- 

 ent types of flagellates. Morphologically, a series representing a 

 gradually increasing complexity is illustrated by : (1) Dimastigamoeba 

 gruberi, in which the blepharoplast arises by division of the intra- 

 nuclear kinetic center and remains connected with it by a centro- 

 desmose or, in this case, a cytoplasmic rhizoplast; (2) Scytmnonas 

 subtilis in which the blepharoplast is not connected with the nucleus 

 and gives rise only to the flagella ; (3) Bodo edax, or species of Cryp- 

 tobia in which a large chromatoid mass, the parabasal body, is con- 

 nected by rhizoplasts with the blepharoplast, or may be indepen- 

 dent of it; (4) Bodo lacertae in which basal bodies (arising from the 

 blepharoplast), blepharoplast and parabasal body are all indepen- 

 dent; (5) Giardia augusta, in which the independent blepharoplast, 

 basal bodies and parabasal body are all double and arranged in 

 perfect bilateral symmetry; (6) Calonympha grassii (Fig. 63), in 

 which nuclei, parabasal bodies, blepharoplasts and basal bodies are 

 multiple and in which axial threads (rhizoplasts) unite to form a 

 central axial supporting rod; (7) Trichonympha campanula, in which 

 the blepharoplast (centroblepharoplast) acts as a centrosome in 

 mitosis while long rhizoplasts connecting distal basal bodies with 

 the blepharoplast form a complex radial system of astral rays (Figs. 

 61 to 65). 



In many cases the blepharoplast, which is the central element of 

 the kinetic complex, remains connected with the nucleus by a rhizo- 

 plast as a permanent record of the intranuclear origin of the entire 

 complex (Fig. 62). In many cases the blepharoplast is double, 

 as in most biflagellated forms; in others it is triple as in Trimastig- 

 amoeba p)iilippinensis or Chilomastix mesnili (Fig. 60, B); in some 

 it is quadruple, or contains four basal bodies as in Trichomonas; in 

 others it is multiple, forming a ring of blepharoplasts about a 

 bundle of flagella as in Lophomonas blattarum (Fig. 105, p. 211). 



