144 
The Ohio N^aturalist. 
[Vol. IV, No. 6, 
insect destroj’s this partition, travels to the end of the tube which 
projects be\’ond the bodj- of the gall, and there makes an opening 
through either the end or the side of the tube and thus makes its 
escape. Examination of j’oung specimens would probably show 
the four zones as well defined as in Diastrophiis nebulosus. 
Part IV. Development of Galls. 
Examination of ver}’ 3’oung specimens of Andricus .seminator 
Harris shows three well defined zones (Figs. 131a, b), the pro- 
tective zone being undeveloped. The fibro-vascular bundles were 
verj- numerous and distributed just beneath the epidermal zone. 
I have examined a large number of these galls of various ages 
and have been unable to find anj' trace of a protective zone. 
Tannin develops in the outer cells verj- earl}- and probabh’ helps 
to form a protection for the larva. 
PLATES XIII-XV. 
112. Section of gall of Pemphigus vagabundus. 
113. Section of gall of Pemphigus rhois. 
114a. Diagram of gall of Cecidomyia pellex. 
114b. Section of gall of Cecidomyia pellex. 
1 15. .Section of gall of Cecidomyia impatientis. 
ii6a. Diagram of the gall of Cecidomj ia holotricha. 
ii6b. Section of the gall of Cecidomj-ia holotricha. 
ii6c. Section of the gall of Cecidomyia holotricha. 
117a. Diagram of the gall of Cecidomj’ia tubicola. 
117b. Section of the gall of Cecidomyia tubicola. 
117c. Section of the gall of Cecidomyia tubicola. 
1 18. Diagram of the gall of Cecidomyia r-iticola. 
119a. Diagram of the gall of Sciara ocellaris. 
119b. Section of normal leaf of Maple 
1 19c. Section of gall of Sciara ocellaris. 
120. Section of gall of Rhodites bicolor. 
i2ia. Section of gall of Ainphibolips conflueutus. (Epidermal and parenchyma zones.) 
i2ib. Section of the gall of .Ainphibolips conflueutus. Nutritive and protective zones.) 
121C. Section of gall of Ainphibolips conflueutus. (Elongated cells in the cavity of the 
parench5'ina zone.) 
122. Section of gall of .Ainphibolips piiinus. 
123. Section of gall of .Ainphibolips sculpta. 
124. Section of gall of .Andricus petiolicola. 
125. Section of gall of .Acraspis erinacei. 
126a. Diagram of gall of Biorhiza forticornis 
126b. Section of gall of Biorhiza forticornis. (Nutritive and protective zones.) 
126c. Section of the gall of Biorhiza forticornis. (Section of protective and epidermal 
zones. ) 
127. Section of the gall of Neinatus pomiiin. 
128. Section of the gall of Holcaspis globulus. 
129a. Diagram of gall of Dia.strophus nebulosus. 
129b. Section of gall of Diastrophiis nebulosus 
130. Diagram of gall of .Andricus coriiigenis 
131a. Diagram of cross section of gall of Andricus seminator. 
131b. Section of j ouiig gall of .Andricus seminator. 
