March 1955]
H.
N.
RAY
AND
B.
S.
GILL
19
RNA, whereas the cytoplasm evidenced only slight reaction and that too just prior
to segmentation. Merozoites liberated from them showed RNA chiefly in the karyo-
some and at their more pointed end (Plate II, Fig. 3).
Second generation trophozoites exihibited marked reaction for RNA only in
the nuclei but when the schizonts were reaching maturity RNA appeared in abun-
dance in the cytoplasm (Plate II, Fig. 4, 5 and 7). Merozoites formed from them
showed RNA chiefly concentrated at the posterior end (Plate II, Fig. 6), though
slight reaction was apparent throughout the cytoplasm and also in the karyosome.
Its 'Goigi' region showed no pronounced reaction for RNA.
Karyosome of microgametocytes throughout gave simultaneously strong re-
action for RNA in the actively dividing nuclei and in the cytoplasm right from the
beginning of their development. In microgametes moderate reaction for RNA
was appreciable in the comma-shaped body only. Nuclei of both microgametocytes
and microgametes always reacted strongly for DNA (Plate II, Fig. 8, 9).
Macrogametocytes gave strong reaction for RNA in the karyosome but with
the approach of maturity the reaction here became lighter but stronger in the cyto-
plasm. Peripheral globules reacted strongly for RNA (Plate II, Fig. 11b). Oocystic
wall gave slight reaction for RNA, but it was pronounced at the micropylar end
only (Plate II, Fig. 11a).
Karyosome and siderophilous body of sporozoites evidenced a slight reaction
for RNA but one or two big lumps of the acid were also found placed round about
the nucleus, especially towards the siderophilous body (Plate II, Fig. 12).
Nucleus of the parasitised cells was always considerably hypertrophied and
contained abundant quantities of a high polymer of DNA; while the enlarged
nucleolus was rich in RNA.
Examination of toluidine blue stained preparations [Brachet's technique,
1953] indicated the same locations of basiphilia at various endogenous stages of
E. tenella as described above.
DISCUSSION
Irrespective of the organisation of any structure, formation of protein molecules
is in general a process of vital importance to all the living matter. Because of the
constant association of nucleic acids with self-reproducing units, e.g. viruses, plastids
genes, etc. the conclusion that the former is involved in protein synthesis becomes
inescapable. Casperssons school of thought believes nucleolus as the chief site of
protein synthesis, but Brachet and his associates attach more importance to the
microsomes, as a major portion of RNA is bound to these ultracentrifugable cyto-
plasmic particles. This hypothesis has been supported by Keller [1949], Hultin
[1950], and Sickevitz and Zamecnik [1951]. They show that incorporation of tagged
amino acids is more rapid in microsomes than in nucleoli. Works of Sonneborn
[1950] London, et al., [1950], Brachet [1950] and Borsok, et al., [1951] tend to strike
a via media between these two hypotheses, in that the participation of nucleus
in protein synthesis is an indirect rather than a direct one. The nucleus probably
controls synthesis or multiplication of microsomes, but these must be the true
agents of protein synthesis. The question how exactly the nucleic acids influence