94 BIOLOGY OF THE PROTOZOA 



chromatoifl body in the c\i:oplasm and closely connected with the 

 basal granule, is a nucleus, or a kinetic center of the cell, or neither. 

 Woodcock's term connotes a happ\' combination of both nuclear and 

 kinetic possibilities; the kinetic function evident from its relation to 

 basal granules or blepharoplasts, while its nuclear characteristic is 

 seen mainly in the deeply-staining chromatin-like substance of which 

 it is composed as well as by its frequent connection with the nucleus. 

 Some writers, notably Rosenbusch (1909), giving free play to the 

 imagination, and under the conviction that it is a nucleus, describe 

 it as such, with centriole, "karyosome," nuclear space which may 

 contain chromatin granules, and a nuclear membrane. The 

 extremely minute size of this organoid and the pranks which the 

 Romanowsky stain or any of its modifications may play with it, as 

 they do with structures of the actual nucleus, together with a fertile 

 imagination, are sufficient to account for the perfect nuclear type 

 which R()senl)usch, for example, describes. Other observers, while 

 maintaining its nuclear character, do not accept this extreme inter- 

 pretation; Minchin, for example, describes it as a "mass of plastin 

 impregnated with chromatin staining very deeply, rounded, oval, 

 or even rod-like in shape" (Prot. p. 288). 



If we bear in mind the many types of granules in the cell which 

 stain like chromatin with certain dyes, it seems unnecessary, to say 

 the least, to make the term nucleus, which stands for a well-known 

 and easily recognized organoid of the cell, elastic enough to embrace 

 cytoplasmic bodies in regard to which there is so little evidence of 

 nuclear structure or nuclear function. In well fixed and stained 

 material the so-called kinetonucleus affords little evidence of nuclear 

 make-up; it appears as a homogeneous mass of chromatoid material 

 which divides into equal parts prior to division of the nucleus. Such 

 features do not make it a nucleus any more than similar features 

 make nuclei of pyrenoids, or of other plastids of the cell. Func- 

 tionally, and unlike the nucleus, it is not necessary for the vital 

 activities of the organism, as shown by the experiments of Werbitski 

 (1910), confirmed by others, in which by the use of certain chemicals 

 the "kinetonucleus" of Tri/panosonia hrucel disappears without any 

 eft'ect upon the movements and reproduction of the trjpanosome, 

 a race being formed in which this organoid is absent. Nor can the 

 "kinetonucleus" be regarded as a centrosome, for although closely 

 connected with basal granules, it never behaves like an attraction 

 center (see Fig. 47, p. 9()). With the exception of Schaudinn's 

 account and the overdrawn account by Rosenbusch there is no evi- 

 dence that it divides by mitosis; it never develops chromatin which 

 by any stretch of the imagination can, be called chromosomes. 



If the "kinetonucleus" is not a nucleus nor an active kinetic center 

 of the cell, then any misleading appellation such as kinetonucleus, 

 centrosome, or blepharoplast, which indicates co-partnership with 



