368 BOTANICAL GAZETTE [MAY 
The bud and apical meristem galls are shown in (7-9). In (7) 
a number of the bud leaves merely become fused, while the other 
two show the transition from the sclerenchymatized polythalamous 
condition with relatively long, aborted leaves forming an invo- 
lucre to the sclerenchymatized monothalamous state with shorter, 
involucre-like elements. In many prosoplasmas of this type the 
involucral structures are suppressed altogether. 
The most primitive cynipid gall is believed to be the variable, 
generally polythalamous, slightly differentiated kataplasma shown 
in (10). From this type through the attainment of the “protec- 
tive” layers the simple prosoplasma (13) is reached, from which 
by reduction to the monothalamous stage an important stock type 
(14) is obtained. This latter, however, may also have been evolved 
through reduction of chamber number before sclerenchymatization 
had taken place (11). The gall is shown in its primitive inter- 
calate position in the leaf. The prosoplasma variant from the 
latter is shown in (12). 
From the concentrically built stock type (14), which is regarded 
as an appendicular form, the greatest evolution in prosoplasmas 
has taken place. Six fundamental lines appear to have sprung 
from it. Certain characters evolved in and characteristic of these 
different lines are in special instances combined in the same gall. 
For example, the stalked type (19) may also exhibit the free larval 
cell condition of (22), as found in Dryophanta pedunculata Bass. 
The combination, however, of two or more of these fundamental 
type characters in the same gall is the less common condition; for 
the most part the galls can be associated with one or the other of 
the structural evolutionary lines. The same tendency, previously 
observed in the Itonididae, toward the formation of a distal false 
chamber, is found (15). This culminates in such a bizarre bracte- 
ate form as that shown in (16), a new gall discovered recently by 
the writer in North Carolina. 
Another striking series is that of the evolution of the radiate- 
fiber type of gall. This begins with the appearance of aeriferous 
tissue in the cortical region (17), and ends with the condition in 
which only the fibrovascular bundles traverse the cortical region 
(18). The type shown in (22) may have been derived from the 
