It was a moment of intense excitement. What forces might not lurk behind the dense walls of _chapparal_, ready to dash upon our ranks as they deployed on the other side? Our artillerists stood to their aimed and loaded guns. The Mexicans were doubtless eager and panting for resistance in the rear of the bristling plants that lined the lofty parapet of the river's bank. Every eye was strained upon the first daring rank that was to plunge into the stream as a "forlorn hope." Mexico would fight now if ever; for her mettle was as yet untried! For an instant, profound silence reigned along the anxious line which the next moment might be involved in the fire of battle. Suddenly the gallant Worth spurred to the head of our troops, and dashing boldly into the flood, waved them on to the further shore. But not a shot was fired by the recreant foe, and as our men rose shouting from the water and rushed up the steeps of the opposite bank they beheld the valiant Mexicans in brisk retreat towards Matamoros! The fugitives were unmolested;--a laugh of scorn and pity ran through our ranks;--and, before nightfall, the first and second brigades of infantry, with a train of two hundred wagons had crossed the stream and encamped three miles from its banks. This was an important affair, as it was the first in which the Mexicans showed themselves in a decidedly hostile attitude; and it furnished an excellent opportunity to try the mettle of our men both in spirit and discipline. Not a soldier faltered. * * * * * On the morning of the 23d of March, General Taylor departed with his whole army from the camp near the Colorado. After a march of fifteen miles he reached, on the 24th, a position on the route from Matamoros to Point Isabel,--distant about eighteen miles from the former and ten from the latter,--where he left the infantry brigades under the command of General Worth, with instructions to press on in the direction of Matamoros until a suitable position for encampment was obtained, at which he might halt, holding the route in observation, whilst the commander-in-chief proceeded with the cavalry to Point Isabel. At that post General Taylor expected to meet the transports from Corpus Christi with the force under Major Monroe, and to make the necessary arrangements for the establishment and defence of a depot. As soon as the army left the Colorado a new object, of more interest in natural history than military memoirs, presented itself to the notice of our troops. The soil was covered with a long wiry grass among which glided immense numbers of huge rattlesnakes, more appalling to our soldiers than the Mexicans. The country literally swarmed with serpents. From the Colorado to within a few miles of Point Isabel their warning rattle was heard on all sides. They crept between the ranks as our men marched through the long herbage, and at night coiled themselves comfortably under their blankets for warmth.