JOURNAL OF ENTOMOLOGY AND ZOOLOGY 163 



mating, oviposltlon, etc., remain unknown, and practically no one 

 has hitherto carried on any further observation on the habits of 

 either the larva or the adult. 



Emergence from the galls of both the male and female adult 

 flies was observed on May 7, 9, 11, 12, 16, 17, 26, 30 and 31. 

 At first a little piece of the epidermis of the gall was broken off by 

 a push from the inside. It was immediately followed by the 

 appearance of a grayish or fleshy white bladder-like ptilinum. The 

 ptilinum seemed to elongate itself to push its way through the very 

 small hole previously made by the larva, and the fly struggled for 

 a little time until the entire head was seen. The head was moving 

 around and the ptilinum itself was expanding and relaxing. Mean- 

 while some minute transparent globules appeared on the surface of 

 the ptilinum. After the entire head had come out of the hole, 

 while the body was still within, a closer examination was made with 

 a pocket lens. It was noticed that the ptilinum covered the entire 

 top portion of the head and extended laterally almost over both 

 eyes, and forward to the base of the antennas. 



Continuing to struggle for a while, the fly gradually squeezed its 

 thorax out of the hole; however, it was still shrugging its shoulders 

 and contracting its back in forcing out more of its body. Almost 

 every part of its upper body, which was out of the gall now, was 

 moving and dragging, and the transparent globules ("sweat 

 drops") on the surface of the ptilinum were increased and decreased 

 constantly. In one case I found the animal came out rather rapidly 

 (it took about 3 minutes), but in others emergence was very slow 

 (about 18-19 minutes). The animal had desperate struggle until 

 the whole thorax and the legs were pulled out and the latter were 

 moving for something to grasp. The difficulty was much lessened 

 when only the abdomen was within the gall, yet a great deal of 

 force was still required for the animal to get itself entirely liberated. 

 The abdomen was much compressed and elongated at first. The 

 body of the animal was much longer and the color was much paler 

 than when mature. The wings were narrowly folded lengthwise. 



Now the animal newly got into freedom was much exhausted, 

 crawling little or staying motionless to rest itself on the surface of 



