ABSTRACT
Although immuni ty and reproductive function are often considered as i f they were entirely separate physiological systems, a moment's considera tion makes their deep and intimate relationship clear. The production of both ova and sperm results i n genetically distinct haploid cells, necessitat ing special measures to prevent attack by the immune system (Hilgarth et al. 1997). Similarly, the fetus is a genetically foreign body, requiring mod ulation of immune function to maintain pregnancy (Grossman 1984; Roberts et al. 1996). More importantly for reproductive ecologists, at a somatic level immune function and reproductive function are balanced against one another as trade-offs under organismic energetic constraints (Hi l l 1993).
