Variation range and “limits of the norm” of relative spleen weight in small mammals from natural populations

Variation in the relative spleen weight was studied in three small rodent species of two genera, Microtus and Myodes. Its range was found to reach 80–94/%.. Regression equations for the upper and lower limits of normal spleen weight were calculated, and its values were shown to lie between 2.0 and 2.0–5.0‰.