6 BRITISH OAK GALLS. . 
being green, is red or crimson, and from it exudes a 
sweet sticky substance. In Dryophanta scutellaris 
there are three distinct layers. Surrounding the 
larva are the primitive nourishing tissues; next is a 
thin layer of bundles of hard cells, these being sur- 
rounded with a thick coating of palisade-like cells, 
with a thin epidermis containing colouring matter. 
Three galls, although plurilocular in growth, are 
widely dissimilar in the covering which surrounds the 
cells when the galls are in perfection of growth. Aph. 
radicis not only has the appearance of a truffle, but 
when cut is very much like one; it also resembles a 
potato, and has the same solid but sappy consistence. 
Although usually below ground, decay is slow. In 
Teras terminalis the texture is looser, but contains 
more sap in proportion; it ultimately becomes spongy, 
and, except the cells, decays during the following 
winter. Andricus ramuli is perhaps unique. The 
little larval cells, massed together to the number of 
ten or twelve, are entirely concealed by a dense mass 
of long white simple hairlets, neither the origin nor 
the structure of which appears to be known. 
A more complex structure is that of Neurvterus 
lenticularis. When examined in September it is found 
to consist of a central mass of cells, full of primitive 
nourishment for the larva which occupies the centre ; 
these the larva consumes before the gall falls. Outside 
these cells are bundles of palisade-like cells, which are 
surrounded with a thick layer of other cells containing 
starch granules, and upon these the larva feeds before 
it pupates. A thick epidermis with chlorophyll 
granules forms the exterior, from which there grows 
numerous hairlets arranged in a stellate manner. 
Cynips Kollari is not only the most complex of British 
galls, but also the most durable. According to Beye- 
rinck (‘ Beobachtungen iitber die ersten Entwicklung- 
sphasen einiger Cynipidengallen,’ p. 142 et seq.), when 
the gall approaches maturity the cellular tissues 
become differentiated -into eight layers: (1) The 
