To those who know them the tropics are not so terrible, treacherous though they may seem. Some enter this zone with a feeling of creepiness as though they were entering a darkened sick-room sheltering some malignant disease. They hesitate to breathe for fear that the very air is poisonous and they may take in the germs of some malady with an unpronounceable name. They shrink from nature as though she had ceased to be the kind mother to which they were accustomed in the colder climates. It is true that there is something horribly creepy and uncanny about this inevitable tropical growth, which is so frail and fragile outwardly but seems possessed of an unconquerable vitality. And yet in many of the so-called unhealthy places, there is scarcely more danger to health than elsewhere, if one but observes the same rules of right living. Continuous hard labour, such as the northern farmer is accustomed to devote to his little farm, is not possible. Exposure to the intense heat of the sun at midday and the heavy rains will bring on fevers and malaria just as surely as it produces the luxuriant vegetation. For this reason the tropics will probably never be suited for colonization by the small farmer who is fascinated with the possibilities offered by land capable of producing two or three crops in a single year. In general, Mexico is poorly supplied with rivers. However, along the Atlantic coast they are very numerous and large, although not navigable for any great distance, or for vessels large enough to be of much aid to commerce. The size of the rivers is due to the great amount of rainfall, which varies from seventy to one hundred and eighty inches annually. When this is compared to an annual rainfall of twenty to forty inches in the northern states of the United States, the conditions in the tropics are better understood. This excessive rainfall washes down earth from the higher ground and this, together with the layers of vegetable mold, have formed soil from eight to fourteen feet in depth thus making it practically inexhaustible. The temperature varies from 70° to 100° Fahrenheit. The Pacific coast has a higher temperature and less rainfall than the Gulf coast. However, there is a stretch of land extending north of Acapulco along the coast and from eight to thirty miles wide that is unrivalled for tropical beauty and productiveness. There are many rivers and streams that traverse this land on the way from the great mountains to the Pacific.