NOTES ON THE ANATOMY OF THE PUNCTATUS GALL 539 
the Structure of the wood of fossil oaks from the Miocene of California 
Eames (7, pp. 1 61-163) found uniseriate rays in his sections, but none 
of the broad homogeneous rays, their place being taken by groups 
of narrow rays aggregated together. Eames also studied the wood 
structure of a number of seedling oaks and found in the group of 
black oaks, to which Q. velutina belongs, that the first broad rays 
formed were similar in structure to those in the fossil oaks. He found 
still further that the homogeneous rays come about through a loss 
of the fibers, etc., in the aggregations of narrower rays, so that the 
compound rays of adult wood are formed after a time by this means. 
In the group of white oaks he found a still more primitive condition 
in the seedling as only uniseriate rays occur for a foot or more above 
the ground and extending through 15-20 annual rings of growth. The 
broad rays of the mature wood arise by aggregation and fusion of the 
narrow rays in the manner just stated. 
Our knowledge of the structure of the oak ray was still further 
advanced by the work of Bailey (2), who found in his studies of 
traumatic oak wood, that the rays formed immediately after wounding 
were all uniseriate. By aggregation and fusion of these the normal 
compound rays result again in subsequent layers. His results seem to 
show that the ancestral conditions of ray structure are possibly reca- 
pitulated in wounded areas. In a later paper, however. Bailey and Sin- 
nott (4) 46, state that seedling stems and roots of Quercus alba, which 
possess only uniseriate rays, will form wide multiseriate rays after in- 
jury, often without indication of the putative stages of compounding. 
In the examination of tangential sections of this gall I found rays 
which were similar in many respects to those figured by Bailey (2, 
pi. XI, fig. 2). In fact a large number of the broad rays in different 
galls showed an inclusion of fibers and other elements to a greater or 
less extent, but usually not so strongly marked as in the ray figured 
by Bailey. This condition led to the supposition that possibly a 
repetition of the conditions described by Eames and Bailey might take 
place in their formation. In order to determine whether this sup- 
position was true or not, one of the smaller galls was selected, and 
tangential sections cut of it from the outermost layers of gall wood 
to the normal wood inside, formed before the gall started. A larval 
chamber was located on this side of the gall, and the section were 
cut at right angles to its long diameter as shown in fig. 2. Every 
other section was mounted in glycerine and preserved in series for 
study. 
