Mauritius is a tropical island of volcanic origin. The high altitudes attained lead to wide variation in precipitation. To windward, and on the higher altitudes this precipitation may be very high; to leeward, protected by the intervening heights, low precipitation is found. There is, too, only a slight difference in temperature at all altitudes. In the regions of higher precipitation, therefore, the conditions are favorable for a rapid depletion of the soils and the parent basaltic matrix in such areas has broken down, leaving lateritic soils which are very infertile.