290 



The Ohio Journal of Science [Vol. XVI, No. 7, 



Plate XIX. 



Fig. 1. Witches-broom. Gall technically confined to proximal ends of branches, 



inconspicuous in the photograph. X M- 

 Fig. 2. Lepidopterous gall of lateral branch. X 1. 

 Fig. 3. Pachypsylla sp. Gall on side of twig. Gall broken open to show the nvmph. 



X 4. 

 Fig. 4. Cecidomyia sp. Gall Xo. 16. An old gall whose chamber was not dropped. 



X3H. 

 Fig. 5. Cecidomyia sp. Immature galls of No. 16 on fruit. The side of the berry 



has been removed to show the galls projecting into the ovulary cavity, the 



ovule in which remains aborted. X 2. 

 Fig. 6. Cecidomyia sp. Mature galls (No. 16) on twigs. Upper galls at stage in 



which the larval chambers are dropped: lower gall older, the tissue dying 



and turning black. X 3. 

 Fig. 7. Galls of Pachypsylla venusta. (gall of petiole). X 14- 

 Fig. 8. Cecidomyia sp. Immature galls (No. 16) on fruit. Normal fruit shown 



near it. X 1?4. 

 Fig. 9. Galls of Pachypsylla mamma. X M- 

 Fig. 10. Galls of Pachypsylla gemma (bud galls) and those of Pachypsylla sp. 



forming ovoid lateral stem swellings. X J4. 



TABLE OF ABBREVIATIONS. 



abc. 1. — abscission layer. 

 ab. xy. — abnormal xylem. 

 ab't. cys. — aborted cystolith. 

 ap. c. tr'm. — apical canal trichomes. 

 ba.- — bast. 



bn. sh. — bundle sheath. 

 ca. — cambium, 

 ck. — cork, 

 cor. — cortex. 



cor. par. — cortical parenchyma, 

 cys. — cystolith. 

 cry. s. — crystal "sac." 

 cu. — cutin. 



deh. 1. — dehiscence layer. 

 diff. p. — differentiated pith, 

 epi. — epidermis. 

 g. cor. — gall cortex, 

 hyp'l. mes. — hyperplasied mesophyll. 

 hyp'l. ph'g. — hyperplasied phellogen. 

 hyp't. pal. — hypertrophied palisade tis- 

 sue, 

 la. — larva. 

 1. c. — larval chamber. 



1. V. — leaf vein. 



lig. scl. — lignified sclerenchyma. 



med. r. — medullary ray. 



m. la. — middle lamella. 



nut. 1. — nutritive layer. 



nym. — nymph. 



p. — pith. 



pal. par. — palisade parenchyma. 



ph. — phloem. 



ph'd. — phelloderm. 



ph'g. — phellogen. 



pr. xy. — primary xylem. 



pro. 1. — protective layer. 



scl'd — scleride. 



scl'd. 1. — scleride layer. 



sim. p. — simple pit. 



sp. par. — spongy parenchyma. 



s. V. — sieve vessel. 



tr'a. — trachea. 



tr'd. — tracheid. 



w. par. — wood parenchyma. 



xy. — xylem. 



