April, 1904 .] 
Galls and Insects Producing Them. 
117 
3. GALLS OF LEPIDOPTERA. 
I gathered a number of Lepidopterous galls on Rudbeckia 
laciniata L. which I was unable to determine. These galls occur 
(jii both leaf and flower and are very large and fleshy. In fact 
they were so fleshy and juicy that it was very difficult to secure 
sections. The parenchyma cells were very large, and small fibro- 
vascular bundles were numerous. The larval chambers were 
numerous and each contained a single larva or pupa. In my 
specimens the larvae were far advanced, many of them in the pupa 
stage, but the cells next to the chambers were ver}' rich in food 
supply. 
Part VII. Root Galls. 
Amphibolips radicola Ashm. (Figs. 76a, b). — on Quercus alba 
L. was the only root gall that I collected. The galls were borne 
just under the surface of the ground at about the point of transi- 
tion from stem to root. Thej' were produced in great numbers 
and so closely packed together as to assume the shape of figs. 
Those nearest the surfa'ce of the ground and therefore slightly 
exposed to the light were of a rich, red color, while those deeper 
in the grotmd were almost white, slightl}^ tinged with 3'ellow. 
Each gall contained from one to five larval chambers. The 
}'ounger galls showed four zones well defined (P'ig. 76a). The 
inner or nutritive zone was thick and the cells contained abund- 
ance of protoplasm. The protective zone was thin and the cells 
fibrous in character rather than sclerenchymatous. The paren- 
chjmia zone was thick and compo.sed of large parench5’ma cells. 
The epidermal zone was relatively thick and the cells firm. As 
the insects approach maturity the nutritive and protective zones 
are entirely destro}’ed (Fig. 76b). The insect eventuallj^ makes 
its escape through an opening in the side of the gall. 
Part VIII. Histology of Galls. 
Many of the histological characters of galls have been referred 
to in the preceding parts. This part has been introduced at this 
time for the purpose of adding a few additional facts which were 
not clear at the time of the writing of the preceding parts. 
y/. hiternal Stuictures. 
I. GALLS OF ACARINA. 
These galls have been sufflcientl)’ discu.ssed and need very little 
attention at this time. In general these galls may be thrown 
into three groups : (i) Those galls in which there is very little 
distortion, but a modification of the epidermis, as in the case of 
the Phytoptus on the beech ; ( 2 ) Convolutions of the parts as in 
the ca.se of P. uhni (Fig. 8), P. abnormis (Figs. 9, 44), P. quad- 
