In the Mediterranean lands, where drought and excessive heat during the growing season offer adverse conditions for agriculture, the small islands, especially those of fertile volcanic soil, show the greatest productivity and hence marked density of population.  Though the rainfall may be slight, except where a volcanic peak rises to condense moisture, heavy dews and the thick mists of spring quicken vegetation.  This is the case in Malta, which boasts a population of 2,000 to the square mile, exclusive of the English garrison.[948] Little Limosa and Pantellaria, the merest fragments of land out in the mid-channel of the Mediterranean, have a population of 200 to the square mile.[949] The Lipari group north of Sicily average nearly 400 on every square mile of their fertile soil;[950] but this average rises in Salina to 500, and in Lipari itself, as also in Ponza of the Pontine group, to nearly 1300.  Here fertile volcanic slopes of highly cultivated land lift vineyards, orchards of figs, and plantations of currants to the sunny air.  But nearby Alicuri, almost uncultivated, has a sparse population of some five hundred shepherds and fishermen.  Panaria and Filicuri are in about the same plight.  Here again we find those sharp island contrasts.

[Sidenote:  Relation of density to area.]

The insular region of the Indian Ocean, which is inhabited by peoples quite different in race and cultural status from those of the Mediterranean, yet again demonstrates the power of islands to attract, preserve, multiply and concentrate population.  This is especially true of the smaller islands, which in every case show a density of population many times that of the neighboring mainland of Africa.  Only vast Madagascar, continental in size, repeats the sparsity of the continent.  An oceanic climate increases the humidity of the islands as compared with the mainland lying in the same desiccating tradewind belt.  Moreover their small area has enabled them to be permeated by incoming Arab, English, and French influences, which have raised their status of civilization and therewith the average density of population.  This culminates in English Mauritius, which shows 540 inhabitants to the square mile, occupied in the production of sugar, molasses, rum, vanilla, aloes, and copra.  In Zanzibar this density is 220 to the square mile; in Reunion 230; in Mayotte, the Comores and Seychelles, the average varies from 100 to 145 to the square mile, though Mahe in the Seychelles group has one town of 20,000 inhabitants.[951]

In the Malay Archipelago, an oceanic climate and tropical location have combined to stimulate fertility to the greatest extent; but this local wealth has been exploited in the highest degree in the smaller islands having relatively the longest coastline and amplest contact with the sea.  The great continent-like areas of Borneo, New Guinea and Sumatra show a correspondingly sparse population; Java, smaller than the smallest