Studies on quantitative morphology. VII. Distribution of interstitium in the thyroid gland

The variability of interstitium percentage values in dog thyroid glands is high, especially in comparison with data from smaller fields. The distribution is generally of the isotrope type, sometimes superimposed by a slight zonal heterogeneity. The low extended interstitium is characterized by a comparatively homogenous arrangement. Whether a net point distance of more than 100 micrograms may cause little deviation from lower values than the true percentage is in most cases not of practical consequence. Often areas larger than 5 mm2 must be measured, or even total sections. Under consideration of the time spent for measuring this can be done only with large net point distances. Low correlation coefficients are observed in these examples for the comparison epithelium: interstitium; and the ratio colloid: epithelium seems to be not always influenced by the interstitium content.