The number of eggs laid per snail in Bradybaena similaris and
the nucleic acids (DNA and RNA) in the albumen gland and
ovotestis were quantified in snails infected with sporocysts
of the digenetic trematode Eurytrema coelomaticum. The total
number of eggs laid per mollusc was reduced by 96.32% at the
end of the larval development. The DNA concentration increased
by 700%, and the RNA concentration was reduced by 8.38% by the
time when the daughter sporocysts of E. coelomaticum were
released from B. similaris. The relation between these values
and the inhibition of the reproduction observed in infected
molluscs is discussed.