1. A statistical analysis is given of the fleece and certain fibre attributes of a shoulder sample of a group of wethers sent from Grootfontein to Onderstepoort for experimental purposes. The data comprise values obtained for three successive years.
2. It is shown that a considerable decrease occurred in the mean values from the first to the second year, and then again an increase to mean values exceeding those existing in the first year. The nature of the change in fibre thickness is given in more detail.
3. The values obtained for each characteristic in the different years are highly correlated, from which fact is deduced the importance of a pre-experimental period.
4. The correlation coefficients between the fleece weight and the fibre attributes are, though significant, not very high, and. the shoulder sample is, therefore, a poor indication of the total amount of wool produced.
5. The ratios of the standard deviations to the corresponding mean values of the group were constant for the three years.
6. Within a shoulder sample a high correlation exists between the coefficients of variability of fibre length for two years, and also between the coefficients of variability of fibre length and fibre thickness for the same year.
7. The interrelationships of the changes in the various attributes are given.
8. The bearing of the above results on experiments in which wool is being investigated, is discussed.