When all is said, Xenophon's information most likely is by far the most trustworthy of any that has been handed down to us, in the same way that his descriptions certainly are the most accurate. Only a few fragments of the book by Simo, written probably about the year 460 B.C., remain; yet even those fragments contain peculiar statements. Thus in addition to insinuating that Thessaly was the only region famous for horses in the centuries before Christ—an assertion indirectly gainsaid by Xenophon—he didactically remarks that the colour of a horse ought not to be taken into consideration when the animal's qualities are being summed up, a statement that the majority of the early writers openly repudiated, and that, as most of us know, is in every country deemed devoid of truth at the present day. Though particulars are difficult to obtain, there is reason to believe that the horse named after the Thracian river, Strymon—owing to its having been bred in that vicinity—and that was immolated by Xerxes before his invasion of Greece, was, as usual, a white horse. By exactly what route horses were introduced into Greece has not been ascertained for certain, but the fact that fossilised remains of horses have not been found in Greece as they have been in many other countries leads to the belief that the horse was not indigenous to the country. From a very remote period, however, we find horses represented on vase paintings; and from these paintings too we are able practically to prove that the Greeks had not rowels in their primitive spurs, but that the spur consisted of a short goad attached to the heel of the boot by means of a strap passing over the instep and another that passed under the sole, almost as the modern hunting spur is strapped on. Spurs of this kind have been discovered in Olympia, also in Magna Græcia, and elsewhere. With regard to the Greek bits and bridles of a later date, the former apparently had no leverage—certainly they had no curb chain—while the pattern of the bridle seems to have remained unaltered. * * * * * As we come nearer still to the time of Christ, we find the young men of Athens growing fonder and fonder of horse racing and taking more pains and spending much time and money in their attempts to improve the breed of horses. And though the soil of Attica was by no means adapted for purposes of horse rearing, it must in justice be said that their attempts met with reward. Thus it happened that about this time—that is to say towards the close of the third or the beginning of the second century—the comic poet, Aristophanes, who died in 380 B.C., began to inveigh against the increasing popularity of horse racing, and against the spread of gambling consequent thereon.