abdomen pressed down between them. From the tip of the abdomen the long, sharp-edged ovipositor, an organ of wonderful delicacy and most remarkable structure, is thrust into the tissue of the pistil, and the eggs are deposited among the ovules. This act may occur several times on the same pistil. Then, still more remarkable, the moth deliberately runs to the apex of the pistil and with tongue and palpi crams a portion of the collected pollen mass into the stigmatic tube, thereby fertilizing the flower. The tongue is worked up and down for some time in the tube like a piston rod, with evident intentness on the part of the moth. This
| Fig. 11.—Pronuba yucasella. |
Fig. 12.—Fruit of Yucca gloriosa. |
series of operations, always in the same order, may be repeated again and again till late into the evening. The moth chooses only the freshly opened flowers and those that have not been punctured by another moth coming before. Only the flowers thus fertilized can ever by any possibility produce fruit; and thus the yucca fruit, as seen in Fig. 12, always bears several constrictions where the scar was made by the puncture of the moth's ovipositor. Inside the fruit the moth-larva develops with the seeds, devouring sometimes a dozen of them; and when the pod ripens the larva eats its way out, and, in the night-time, drops to the ground by a silken thread, burrows into the soil, and there wraps itself in a strong cocoon. Sometimes the moth does not issue
