AbstractInternal drainage was studied on Mikkaglaciären and Storglaciären in northern Sweden by means of salt injections. The internal drainage of Mikkaglaciären was found to occur in two separate systems in semilateral positions, systems corresponding on the surface of the glacier to areas of crevasses with different strike directions (cf. Stenborg 1968). The relative amounts of ablation for the different areas could be correlated with the discharge in the corresponding frontal streams.The drainage model devised for Mikkaglaciären is assumed to be valid for other glaciers with the same main characteristics. It appeared to be applicable to Storglaciären, with one exception, caused by a topographical anomaly. In connection with this anomaly, a re-arrangement of the drainage took place between the two years of observation (1960 and 1968).Summaries of the investigations and conclusions concerning Mikkaglaciären and Storglaciären are given on page 26 and on pages 30 and 34 respectively. Some general views on methods (use of tracers), on the physical possibilities of drainage penetration and the development of internal drainage courses, and on the glaciological and morphological applicability of the drainage model devised for Mikkaglaciären are given in separate sections (pp. 14 f. and pp. 36 ff.).