Abstract
Eggs of T. colubriformis and H. contortus were separated from faeces. Their response to desiccation was compared by subjecting them, at different stages of development, to a range of relative humidities. Many eggs of T. colubriformis at all stages of development survived desiccation at relative humidities down to 75%, whereas the only H. contortus eggs to survive were those exposed to the highest relative humidity and which had already undergone a substantial amount of development before desiccation.