If to these causes, which operate so powerfully toward the decrease of the indigenous race, is added the sensible diminution it has suffered in our civil wars,--since the indigenous race supplies far the larger part of the army--the truth of my assertion seems fully corroborated. THE SEASONS IN THE VALLEY OF MEXICO. Few must be the places in the world which, from the picturesque and poetical point of view, surpass in beauty the Valley of Mexico. The varied phenomena, which the seasons of the year there present, powerfully contribute to this. Some European savants assert that the seasons of the year are, in the intertropical regions, reduced to two, the dry and rainy seasons. In our country this assertion is without foundation. The truth is, that, in those regions, weather variations less sharply determine seasonal changes than in the temperate zones; but, in the Valley of Mexico seasonal changes really take place as shown by the beautiful fresh mornings of its Spring, prodigal in exquisite and varied flowers; the hot days of its rainy Summer, rich in delicious fruits; the warm afternoons of Autumn with its wondrously beautiful drifting clouds, and the cold nights of Winter, with its clear and starry sky. As the last hours of night shorten in the lovely season of Spring, the deep darkness which envelopes the earth’s surface dissipates little by little and objects become visible as the delicate light of dawn gradually invades the east. The sun’s rays, propagating themselves with a constant undulatory movement, cause successive reflections and refractions, in the atmosphere and clouds, scattering the light in every direction and permitting the distinguishing of objects not yet directly illuminated by that body. If this light, known by the name of diffused or scattered light, did not exist, the shadow cast by a cloud, or by any object whatever, would produce the darkness of night, and--there being no twilight--the sun would appear on the horizon suddenly and in full splendor. The sweet trills of the goldfinch, the warbling of other birds, the harmonious sound of bells, which announce in the towns the hour of dawn, and the laborer, who betakes himself to the field, with his oxen, to begin his daily labors, mark the moments in which the splendid rays of the sun, which precede the rising of the luminary, diffuse themselves through the transparent fluid of the atmosphere. Before the sun mounts above the horizon the eastern heavens are successively colored with the brilliant tints of red, orange, yellow, green, and purple; the limit of the white light of dawn, extending in the form of an arch through space, rapidly advances toward the zenith, while, at the same time, the upper heavens about that point, gradually acquire the most intense hue of azure.