"I shouldn't think they would know enough to follow their leaders even if they had any," remarked Donald. "Well, you see there is a sort of instinct born in 'em to tag after each other. Besides, they learn to follow by playing games. Yes, indeed," protested Sandy, as Donald seemed to doubt his words, "sheep are very fond of games. There are a number of different ones that they play. The one they seem to like best is 'Follow the Leader.' I don't know as you ever played it, but when I was a lad I did." "Of course I have played it. We used to do it at recess." "Well, the sheep like it as well as you, and it is a lucky thing, for it teaches them one of the very things we want them to learn. They will often start out, one old sheep at the head, and all the others will fall into line and do just what that sheep at the front does. So they learn the trick of keeping their eyes on a few that are wiser than they, and doing what the knowing ones do. They seem to have no minds of their own--they just trail after their leaders. If we can get leaders that are able to see what we want done it is a great help." "I should think so!" "When we have selected our leaders we then scatter markers through each band of sheep." "And what are markers, Sandy?" "For a marker you must take a black-faced sheep--or, mayhap, one with a crumpled horn; he must have something queer about him so you will know him right off when he is mixed in with the flock. We put these markers at the beginning of every hundred sheep. It makes it easier to keep track of the herd." "I'm sorry to be so stupid, Sandy," Donald said, "but I don't think I just understand about the markers." "We have two thousand sheep in a band," explained the herder kindly. "Now if one of our markers is missing we reckon that a hundred sheep are gone. No one sheep ever strays off by himself, you may be sure of that. When sheep stray they stray in bunches. If a marker wanders off you can safely figure that a lot of those around him have gone too. Roughly speaking we call it a hundred." "But when you have such big bands of sheep and they are moving about I should not think the markers would be in the same place twice," persisted Donald, determined to fathom this puzzling problem. "You dinna ken sheep, laddie! They are as jealous to keep their rightful place in the flock as school children are to get the first place in the line. They will fight and fight if another takes the position that belongs to them. It is a silly idea, but an aid to the herders." "And so the leaders and these markers really help the shepherds to manage the flock?" "Aye. But you're leaving out the shepherd's best helper." Sandy's face suddenly softened into tenderness. "His best helper?" repeated Donald. "Aye, laddie! His dogs!"