In like manner they divide the cavalry into ten squadrons (turmae) and from each they select three officers (decuriones), who themselves appoint three rear-rank officers optiones).
The first commander chosen commands the whole squadron, and the two others have the rank of decuriones, all three bearing this title. If the first of them should not be present, the second takes command of the squadron.
The cavalry are now armed like that of Greece, but in old times they had no cuirasses but fought in light undergarments, the result of which was that they were able to dismount and mount again at once with great dexterity and facility, but were exposed to great danger in close combat, as they were nearly naked.
Their lances too were unserviceable in two respects. In the first place they made them so slender and pliant that it was impossible to take a steady aim, and before they could fix the head in anything, the shaking due to the mere motion of the horse caused most of them to break.
Next, as they did not fit the butt-ends with spikes, they could only deliver the first stroke with the point and after this if they broke they were of no further service.
Their buckler was made of ox-hide, somewhat similar in shape to the round bosse cakes used at sacrifices. They were not of any use for attacking, as they were not firm enough; and when the leather covering peeled off and rotted owing to the rain, unserviceable as they were before, they now became entirely so.
Since therefore their arms did not stand the test of experience, they soon took to making them in the Greek fashion, which ensures that the first stroke of the lance-head shall be both well aimed and telling, since the lance is so constructed as to be steady and strong, and also that it may continue to be effectively used by reversing it and striking with the spike at the butt end.
And the same applies to the Greek shields, which being of solid and firm texture do good service both in defence and attack.
The Romans, when they noticed this, soon learnt to copy the Greek arms; for this too is one of their virtues, that no people are so ready to adopt new fashions and imitate what they see is better in others.
Walbank Commentary