70 Journal of Agricultural Research voi. x, Noa 



At the end of May the galls were as large as % inch in diameter on 

 large leaves, whereas those on naturally small leaves were mostly under 

 }4 inch. During June the galls developed rapidly, assuming an oblong 

 saclike or baglike appearance, the portions of leaf between the lateral 

 ribs became much distended, and the ribs thickened abnormally. The 

 external color varied from pale yellowish white to purplish brown, the 

 majority of the galls exposed to sunlight being rosy and those in shady 

 places light green or yellow with purplish blotches. Toward the end of 

 June (June 21) the galls averaged i^i by iX inches, and specimens as 

 large as 2^ by i^ inches were observed on unusually large leaves. 



By July 8 the largest specimens measured 4 by 2>^ inches, the smallest 

 did not exceed % inch maximum diameter, and the average size was 

 about 1% by i^ inches — a slight increase in size over that existing on 

 June 21. By the first week in July the galls have attained their full size; 

 and, soon after having been forsaken by their inmates, they turn brown 

 all over and become brittle but remain attached to the twigs in large 

 numbers all through the winter succeeding (PI. 10, E). 



Mature galls frequently comprised the whole of a leaf, as in Plate 10, 

 B and C, while in other instances only one side of the midrib is affected. 

 Less frequently two or more separate galls occurred on the same leaf, 

 and galls were more usually found on leaves at the base of the year's 

 growth because the young stem mothers on most trees hatched at the 

 time when the first leaves of the spring growth were unfolding, and set- 

 tled on the earliest leaves. The twig illustrated in Plate 10, B and C, is 

 an exception and occurred on a tree which threw out much of its foliage 

 before the stem mothers hatched. 



The mature fundatrix deposits young prolifically, and her body rapidly 

 swells. Four individuals under observation deposited each about 75 

 young in three weeks, when the eldest matured as second-generation 

 wingless forms (fundatrigenia). No definite records were obtained of 

 the total progeny of the stem mothers, but it appears that they may 

 deposit as many as 300 young during the four or five weeks in which 

 they are alive in the adult state. It should be remarked that galls have 

 been collected in July which contained upwards of 1,000 larvae and pupae, 

 but it could not be ascertained whether these were the progeny of a single 

 fundatrix, of several fundatrices, or the combined progeny of fundatrices 

 and wingless viviparous females of other generations. 



The newly hatched progeny of the stem mother are pink or light car- 

 mine, and elongate; the dorsum of the head is gray; the eyes are red; the 

 thorax is light hyalin yellowish pink; the appendages and beak are hyalin 

 whitish; the leg joints are narrowly dusky gray; the tarsi and tip of the 

 beak are dusky gray. The larvae remain pink during their early growth 

 and are deeper in color after molting. During the last two immature 

 instars the body darkens and assumes a pyriform color, but the pupae 

 are elongate. 



