234
MUCOPOLYSACCHARIDES IN EIMERIA TENELLA
[ Vol. XXIV, Part IV
in a medium which possesses potent coagulating power and is literally flushing and
perfusing each cell of cæcal mucosa, the cellular structure of which has been disrupted
and dishevelled by schizogony. In order to initiate gametogony they have to swim
through this hostile environment long distances in search of fresh cells, which have
become scarce as large areas of cæcum have already sloughed away due to
extensive parasitisation. Provision of high concentrations of anticoagulating
mucopolysaccharides in merozoites seems not to be an extravagant, wasteful and
mere fashionable array of this carbonaceous material but it stands to reason, to
infer, that it is a well-designed and purposeful effort on the part of the parasite to
ensure perpetuation of the race. Of the millions of merozoites produced, a large
number is eliminated with cæcal evacuations, a fair proportion dies an 'infant's
death either due to an inherent weakness or their inability to stand the hazards of
tissue-reaction. Only a small proportion, therefore, of the total population survives
to initiate gametogony.
Mucopolysaccharides appear to discharge yet another function in sporozoite,
and in both first and second generation merozoites. Their hydrotropic property
attracts water from the surrounding cytoplasm of host cell. This imbibition of
fluids by the parasite through osmosis gives it the turgidity and rounded appearance,
as with a spherical shape it can hold maximum volume of fluids. Within the host
cell a more fluid zone is created in which the parasite is suspended. During
fixation due to the differential shrinkage between the parasite and host cell, this
zone appears as a vacuole.
In sexual stages there is a sensible distribution of mucoid sulphate. Macro-
gametocytes contain a poor amount of mucopolysaccharides in their cytoplasm-
nucleus and its membrane. But with the approach of maturity concentration of
both the mucopolysaccharides rises in the ground substance of cytoplasm. The
peripheral globules are replete with HAP.
Microgrametocytes possess relatively greater amount of mucoid sulphate, the
highest concentration of this substance is present in comma-shaped bodies of
microgametes. High concentration of mucopolysaccharides in male gametes can
also be explained in the light of their future physiological activity. They have to
swim through a coagulating medium to fertilise macrogametes. Presence of
hydrotropic substance in the body of microgamete, will undoubtedly help it in pro-
ducing an intimate contact with the egg membrane, and facilitate its passage through
the egg cytoplasm to reach the female gamete's nucleus. During fertilisation the
nucleus is in a fluid stage to allow free chromosomal interplay and also to maintain
a close contact between enzymes and substrate.
The process of fertilisation provides a stimulus to the peripheral globules to
discharge their acid contents which coalesce to form oocystic wall rich in hyaluronic
acid type polysaccharide. The whole physiological activity of the oocyst is de-
pressed for the time being, consequently the concentration of mucopolysaccharide
has also fallen to a low level as is evident from their staining reactions. The nuclear
membrance of the zygote is not discernible.
After fertilisation hyaluronic acid in the oocyst wall appears to serve a useful
purpose in carrying the oocysts undamaged through the acid medium of proventri-
culus into the duodenum. Here, trypsin in the presence of an alkaline medium