human
Don't you see, _sobrino mio_, that one of us can stay by the end of the trail we've already made, or two for that matter, while the third rides forward. The others can call after to keep him in a straight line and to the course. The three of us following one another, and the last giving the directions from our trail behind, we can't possibly go astray. Thanks to that white stuff, our back-tracks can be seen without difficulty, and to a sufficient distance for our purpose.