INTRODUCTION. 5 



comparatively low. It rises gradually to the central region and then 

 sinks towards the foot of the Ghats. This is shown diagrammatically 

 in Fig. 3, PI. I, in which the stream and river valleys are omitted. 

 Section I, PI. VIII (near Tanur to Manarkcid) shows the present state 

 of the plateau, cut up in every direction by valleys. 



The plateau slopes from its central point (about Pandalur Hill), not 

 only to the west and east, but also to the north and south. The slope 

 is very gentle, rarely greater than a quarter of a degree. Towards 

 Ariakod (on the Beypore River) and towards the coast, the angle 

 of inclination is about 15' to 18', and it probably never exceeds 18'. 



The resemblance to a plain of marine denudation is perfect, the 

 highest part being in the neighbourhood of Urotmala, Pandalur, and 

 Pranakod Hill, which must have been islands before the plateau 

 began to rise above the sea. 



If the whole country sank about 500 feet, these hills would be 

 islands lying in the middle of a bay, the coast being at the foot of the 

 Western Ghats. This was no doubt the condition of Malabar before 

 the laterite period. As the land rose, a ledge formed round the chain 

 of islands (Urotmala, &c.) ; and this ledge gradually grew outwards till 

 it reached the Ghats. The plain of marine denudation started from 

 these islands as a centre. On other parts of the west coast, where 

 there were no bays and no outlying islands, the plain probably started 

 at the foot of the Ghats and grew outwards to the west. In those 

 places, therefore, the plateau slopes from the Ghats to the sea. 



The highest part of the plateau lies in the centre of the area 



described, and is separated from the hills on the 

 Rivers. 



north, east, and south (the Wynaad, Nilgiris and 



Pdlgha't Hills, and the Cochin Hills) by lower land, forming a ring- 

 shaped depression or moat round it. The Beypore and Ponnini 

 Rivers flow in this moat and receive tributaries, the former from the 

 south and the latter from the north, which flow round the eastern side 

 of the central high land ; so that this high land is almost surrounded, 

 except towards the sea, by the basins of these two rivers. The chief 

 drainage of the high land itself finds its way into the Kadalhundi 

 River, which takes its rise in Pranakod Hill. 



( 205 ) 



