The distribution of gastro-intestinal nematodes collected from lambs was investigated using the Taylor's power law index of aggregation beta, which is known to be independent of the mean population size. For 12 out of the 15 nematode species investigated the estimate of beta was not significantly different from 2.0. For these species a logarithmic transformation would stabilize the variance of the distributions prior to further statistical analysis. The remaining species had values of beta which were significantly lower than 2.0. For these species a variance-stabilizing transformation is given by z = x1-beta/2.