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



fully as green as the leaf. Coarsely pubescent. The chamber 

 is constricted distally. Galls not uncommon in Kansas, but 

 this form has not been seen in Ohio. 



The writer is practically certain that this is the gall described 

 by Pergande, whose notes are presented by Felt with the descrip- 

 tion of the above insect. Pergande states it to be a "very 

 hard, obconic gall, the upper extremity produced as a long 

 slender nipple; at the base five or six low ridges. The galls 

 occur on the upper side of the leaf and drop when mature." 

 Unfortunately no measurements are given. On the basis of 

 the brief description, however, absolute certainty is not possible. 



Felt, N. Y. State Mus. Bull. 180, p. 216. 19U. 



The histology of this form, (PI. XVIII, Fig. 9a), while 

 fundamentally similar to that of C. unguicola, just described, 

 presents many points which are of particular interest when 

 contrasted with the features of the other gall. 



A specimen on the leaf was chosen so that the two galls 

 can be said to have a similar origin. The distal expanded 

 or flaring portion of this gall (8) is seen to be due to the develop- 

 ment of a mass of large celled parenchyma, comparable to 

 that found in the proximal part of 7. The protective layer 

 is thicker and divides distally so as to form a definite support 

 for the mass of parenchyma just mentioned. The nutritive 

 layer is extremely well developed; the thickest of any of the 

 itonid galls. It will be noted that it is intact. The apical 

 canal of the gall is not continuous into the chamber, the walls 

 at its inner end having become tightly pressed together. The 

 line between the two epidermises, however, was easily found in 

 the serial sections used. The outer part, of definite diameter, is 

 choked with slender trichomes, which are certain of the epi- 

 dermal cells greatly elongated. The fibro-vascular bundles 

 traverse the protective layer. Much more of the leaf is involved 

 in this gall than in number 7 (Fig. 9a). In that portion of the 

 leaf involved, the usual inhibition of the normal differentiation 

 has ensued, the hyperplasia consisting of little more than a 

 mass of parenchyma bearing greatly hypertrophied epidermal 

 cells (gall trichomes) and the vascular tissue. As in all of these 

 galls, no cystoliths or stomata ever were seen associated with 

 the hyperplasia tissue. The longitudinal section of the larva is 

 indicated in the chamber. 



