
studies on loiasis in monkeys.
iv.--experimental hybridization of the human and
simian strains of loa
in the cameroons rain-forest there exist two strains of loa, each apparently
evolving in its own host-vector complex (duke and wijers, 1958).  the natural
simian parasite which is found most abundantly in the drill (mandrillus
leucophaeus), is characterized by the large somatic size of the adult worms
and microfilariae and by its nocturnal microfilariae periodicity.  it is
transmitted among the monkey population by the crepuscular canopy-dwelling
chrysops langi and c. centurionis.  the natural human parasite has diurnally
periodic microfilariae and is transmitted by the day-biting anthropophilic
c. silacea and c. dimidiata (bombe form).  it can also be transmitted
experimentally to the drill, in which host the parasites are of small somatic
size and maintain their diurnal periodicity.
as the two strains of contrasting periodicity can be maintained in drills, it
was decided to try cross-mating them to produce hybrids.  the present paper
describes the methods by which this was done, records the characteristics of
the hybrid parasites, and suggests that, when interbreeding, the two strains
segregate according to a simple mendelian pattern as regards periodicity and
somatic size.
