All of these data support the possibility that the eyestalk controls diuresis, either as a source of a diuretic-promoting factor or through some indirect mechanism. However, in other work, eyestalk ablation resulted in an increased volume of urine, perhaps through the removal or inhibition of an antidiuretic factor . The resolution of these apparently conflicting observations is confounded by the use of different species collected at different seasons and often used at various stages in the molt cycle. We believe that our culture systems diminish the degree of physiological heterogeneity compared to that observed in collected animals.