Page:Popular Science Monthly Volume 38.djvu/73

Rh. This tortoise has not been seen since 1886, so it has probably died. Another, which has been observed for the past nine years, was marked with the inscription "C. B., 1849"; as the letters and date were so much worn as to be but faintly discernible, they were doubtless reliable. This old animal was found for the last time, dead, in the summer of 1889. Another, bearing the date 1851, is still alive. Assuming that the tortoises were full grown, or about twenty years old when marked, we are safe in stating the period of their lives as from sixty to seventy years. No doubt some individuals may reach a century or over. Unfortunately for science, it is a common sport for the country urchin to engrave tortoises with dates varying from forty to fifty years before the artist's birth. This, however, can almost always be detected, for the inscription becomes very faint after thirty years of rubbing over the ground. In fact, it would seem impossible that an inscription could last for a hundred years, as the growth of the shell and the constant friction would probably obliterate it.

The tenacity of life in all tortoises is remarkable The heart will continue to pulsate for over three quarters of an hour after being cut out of the body, and the animal is said to have lived for several months after the brain had been removed. There seems to be fully as much fat about the muscles of tortoises which have just awakened from the winter's sleep as there was in the preceding autumn. Doubtless they could remain torpid for over a twelvemonth, and then recover.

The mating season of our box tortoise occurs during the first three weeks in May. The males are unusually active during this period, and will fight savagely among themselves. The author was once fortunate enough to witness one of these combats. Two old males were facing one another; using the front flaps of their plastrons for shields, they would charge, snapping viciously, and whenever one obtained a grip he would hang on with bull-dog tenacity. The noise made by their shells knocking together could be heard two hundred feet away. After an hour or more the smaller male began to show signs of exhaustion, his charges became weaker and weaker, until finally he closed his shell tightly and refused to fight. The victor, after snapping at the unresponsive shell for a few moments, crawled deliberately over the back of his shut-up adversary. It was found upon examination that neither of the combatants had received any visible injury, so well did their armor of shells and scales protect them.

All turtles are oviparous, depositing their eggs in the ground and leaving them to be hatched by the heat of the sun. The laying period of our box tortoise extends from the 7th to the 20th of June. A few females lay in the autumn, but this seems to be a perverted instinct, and not a regular habit of the species. They