268 
The Ohio Naturalist. 
[Vol. II, No. 7 , 
of this paper. The parenchyma is divided into two very distinct 
zones, the larval chamber occupying the lower part of the inner 
zone. The inner zone cells have much thinner walls than those 
of the outer cells. Surrounding the larval chamber is a zone of 
cells which stain very deeply and probably furnish nourishment 
to the larva. The epidermal cells are small. 
Callirhytis tumi/ica O . S. (Fig. 26 a. b.) is a small, fleshy, solid 
gall projecting on both sides of the leaf and resembles N. irregu- 
laris (Fig. 25), except that it is a little larger, does not have so 
many larval chambers and is smooth. It presents the simplest 
characters studied, showing the characteristic small, more or less 
cubical epithelial cells, the lack of differentiation into palisade 
and mesophyll, and the two zones. The outer zone is very thick 
2nd is in contact with the inner zone. The inner zone is narrow 
and lies near the large larval chamber. At the point of union of 
the two zones the cells are very small. The outer zone can be 
readily subdivided into epidermis and parenchyma, but the inner 
zone cannot be subdivided into two sub- zones unless we consider 
the layer of small cells as the protective sub-zone. However, 
this sub-zone of small cells does not possess the sclerenchyma 
character described by Fockeu for the Cynipidae galls. 
Holcaspis centricola O. S. (Fig. 27 a. b. c. ) is a large, spherical 
gall projecting both above and below the leaf. In this we have 
the two zones, but each retaining the characters previously 
described ; the cells of the inner zone, however, being smaller 
than in C. tumifica. The epidermal cells have thicker walls than 
in any other Cynipidae gall examined. The two zones are con- 
nected by fibro-vascular bundles. In this the four zones of 
Fockeu are quite well defined : The outer zone forming the very 
distinct epidermis and parenchyma ; the inner zone showing a 
fairly well defined protective and nutritive part. 
Amphibolips inanis O. S. (Fig. 28 a. b.) shows a very striking 
resemblance to H. centricola (Fig. 27), except that it is much 
larger. The epidermal cells do not have such thick walls as in 
H. centricola and are much longer and narrower. The inner zone 
is readily subdivided into the protective and nutritive sub-zones 
described by Fockeu. The inner or nutritive sub-zone is made 
up of tliin-walled cells with prominent nuclei, the outer or pro- 
tective sub-zone of sclerenchyma cells. The connection between 
the two main zones is by means of fibro-vascular bundles, the 
same as in H. centricola. 
Dryophanta palustris O. S. (Fig. 29 a. b. c. ) presents a condi- 
tion very similar to the two preceding galls, H. centricola (Fig. 
27) and A. inanis (Fig. 28), except that the fibro-vascular bundle 
connection between the two zones is not present ; the inner zone 
containing the larva forms a sphere which is free in the large 
chamber formed by the outer zone. 
