On one occasion at 11 p.m. Colonel J---- and the writer found Zivy cave as welcome a sight as ever struck the eye of man. Coming into the trenches, we stumbled into a heavy Hun artillery barrage. After a number of close shaves, in two of which we were buried in mud from the exploding shell, we were heavily dragging our feet through the thick mud of Guillermot trench when a shell struck full in the trench twenty feet in front of us, nearly bursting our ear drums. We pressed closely against the wall of the trench, awaiting the next. It came almost immediately, landing thirty feet behind us,--bracketing us. "The next will get us, sir," I said. "Not on your life, doctor," cheerfully replied Colonel J----. And he was right, for a few moments later we were stumbling into the entrance of Zivy cave, and that slimy, dark, four-foot opening was more welcome to us than would be today the spacious rotunda of the Savoy. I always admired the Colonel's cheerful confidence, but, as Kelly well said, "Confidence is a foine thing, but it raly has very little affict in stoppin' a Hun shell that's comin' yer way." This, the Colonel unfortunately found out in the Battle of Arras. From one of these deep caves on the Vimy front previous to the battle of Easter Monday, tunnels miles in length, electric lighted, were built, leading to different headquarters, aid posts, ambulance depots, and to various points in No Man's Land. They were of inestimable service when the day of battle arrived. No doubt they will be among the show-places of France to encourage tourist traffic after the war. The entrance to deep dugouts is usually only high enough to go through in a stooped position; and in this case the easiest way to enter them is to back down. After some practice one gets accustomed to this manner of progression, and it becomes easy--as if our bodies had reverted to the days of our cave-dwelling ancestry to accompany the turning back of civilization's clock. The two entrances preferably point away from the enemy lines, but in case of advance the enemy dugouts may be taken over in spite of the fact that their entrances seem to invite a shell to enter. And, rather strangely, shells rarely seem to make a straight hit on an entrance.