Where the subglacial streams did not follow subglacial valleys, they did not always find valleys when they issued from the ice. Under such circumstances, each heavily loaded stream coming out from beneath the ice must have tended to develop a plain of stratified material near its point of issue--a sort of alluvial fan. Where several such streams came out from beneath the ice near one another, their several plains, or fans, were likely to become continuous by lateral growth. Such border plains of stratified drift differ from valley trains particularly (1) in being much less elongate in the direction of drainage; (2) in being much more extended parallel to the margin of the ice; and (3) in not being confined to valleys. Such plains stood an especially good chance of development where the edge of the ice remained constant for a considerable period of time, for it was under such conditions that the issuing waters had opportunity to do much work. Thus arose the type of stratified drift variously known as _overwash plains_, _outwash plains_, _morainic plains_, and _morainic aprons_. These plains sometimes skirt the moraine for many miles at a stretch. Overwash plains may sometimes depart from planeness by taking on some measure of undulation, of the sag and swell (kame) type, especially near their moraine edges. The same is often true of the heads of valley trains. The heads of valley trains and the inner edges of overwash plains, it is to be noted, occupy the general position in which kames are likely to be formed, and the undulations which often affect these parts of the trains and plains, respectively, are probably to be attributed to the influence of the ice itself. Valley trains and overwash plains, therefore, at their upper ends and edges respectively, may take on some of the features of kames. Indeed, either may head in a kame area. Good examples of overwash or outwash plains may be seen at various points in the vicinity of Baraboo. The plain west of the moraine just south of the main quartzite ridge has been referred to under valley trains. In Sauk Prairie, however, its characteristics are those of an outwash plain, rather than those of a valley train. [Illustration: Fig. 41.--The morainic or outwash plain bordering the terminal moraine. The figure is diagrammatic, but represents, in cross section, the normal relation as seen south of the quartzite range at the east edge of Sauk Prairie, north of the Baraboo river and at some points between the South range and the Baraboo.]