One belief of man’s growth is that when as a proto-human he faced a more severe climate, he was forced to work harder and so survived and started on the road to civilization. But this negative theory fails to explain why man did not retreat to the tropics or else like other species merely die off after a few uncomfortable lingering generations.

Another theory of survival stresses weather instead of climate. When the gentle epoch ended and storms became many and violent, then those very storms—the shock of constant adjustment—stimulated man out of his tropical languor, and gave him power and will to outface a harsher world. With each storm and passing front, blood pressure rises and falls, nerves react, secretions alter. So physicians have learned, and they quote from Hippocrates, father of medicine: “Air is lord.”

Some theorists say even that civilization can flourish only in the lands along the storm-track, where man most often feels the bracing shift from warm and moist to cold and dry, back and forth. For evidence, they point to Ptolemy’s records, which seem to show that in their times of greatness the Mediterranean lands knew more turns of weather than now in these decadent days.

This marriage of civilization and storms has not been proved, or yet refuted. If it is true, then those atmospheric powers which seem to overwhelm men in the temperate zone, also stimulate the energy to live and conquer. Civilized men are like Napoleon’s grenadiers—they always grumble, but they always march.

2

At Brownsville men weary from tending fires fell into bed, and slept the peaceful sleep of those released from fear; at Montemorelos the brown-skinned people no longer shivered upon their straw-mats. The still cold of the night was broken. The oranges were safe, and the fires might burn low. On this side the Rio Grande and on the other, a softer air was moving from the Gulf. Whether women had prayed to the Son or called upon the dark Virgin, whether men had cursed or been silent, upon all the orange groves the gentler wind was blowing. On the coast of Texas and the coast of Tamaulipas, no matter the flags, it blew.

No longer did the stars glitter coldly in the cloudless sky and the heat drain off to outer space. Now, in the darkness before dawn, from Galveston Bay to Río Pánuco the overcast hung low; as the moist air blew across the cold land, long arms of fog moved up every valley.

Mile by mile the southern breeze pushed inland. Monterrey felt it, and Saltillo; it moved in the streets of Laredo. It came to San Antonio and Houston, to Austin and Waco. Reaching far to the north along Trinity River a finger of mist touched Dallas. And even farther, along the Red River and the Cimarron, men waking in the night knew that the power of the cold was breaking.