Mayhew 1952 Experimental June 19 Mallard E 42 This afternoon 1 M 23 egg at 75% hatched. Another M 23 is pipped at 75%. June 20 One M 23 egg at 65% hatched this morning. All unpipped eggs were dipped this morning. Those dipped were: 40% - 5 M 31 eggs ; 6 G 24 eggs 65% - 4 M 31 " ; 4 G 24 " 75% - 1 F 31 " ; 6 G 24 " 85% - 2 F 31 " ; 3 G 24 eggs ; 4 M 31 eggs 90% - 2 M 31 eggs One G 24 egg at 75% was spoiled (unfertile), so it was not dipped. 1 G 24 egg at 40% + 2 M 23 eggs at 75% hatched this afternoon. June 22 One G 24 egg hatched at 65% this morning. 1 G 24 egg at 75% + 2 G 24 eggs at 85% are pipped. June 24 One G 24 egg at 75% hatched this morning. June 25 All remaining 31 eggs were dipped today. Also, 3 eggs from 85% were broken open; 2 G 24 eggs were pipped too soon. 1 F 31 egg was infertile (rotten). June 26 Today 4 M 31 eggs at 65% were pipped. June 27 Today 3 M 31 eggs at 65% had hatched, the other M 31 egg at 65% was still alive. June 28 The last M 31 egg at 65% hatched (of the 4 pipped eggs of 6/26/52). June 30 One F 31 egg at 75% + 1 M 31 egg at 85% hatched today.