597 
the articulation of the jaws (III), in the floor of the mouth on either 
side of the base of the tongue (VI). These tonsillar patches may be 
respectively termed for descriptive purposes, the Preglottideal, 
Lateral, and Sublingual tonsils. To these should probably be added 
however the Choanal tonsils (VIII). 
A certain variability characterizes the patches in all the regions 
where they occur, both in the size and exact location. This applies 
to the preglottideal, lateral and sublingual tonsils as well as to the less 
constant patches. Thus, in the case of lateral patches, two may occur 
on the same side (83 mm), more frequently but one on a side was 
found, while once (62 mm) it could be identified on one side only. In the 
case of the dorsal patch (II), for example, in one (70 mm) it is me- 
dial, in one (68 mm) medial and left, in two (60, 83 mm) it is on the 
right side. It varies also in size and apparently somewhat in cephalo- 
caudal position. In all these patches, with the exception of the sub- 
‘lingual tonsil of the toad later to be described, a size difference between 
the right and left sides is usually appreciable, but neither right nor 
left side seems to be favored in the size descrimination.') 
Since these structures only appear after metamorphosis, it is 
particularly desirable to follow through the transformations under- 
gone by the regions where the tonsils subsequently make their appear- 
ance. This has been attempted however, only in the case of the three 
most constant tonsillar patches, — the preglottideal, lateral, and 
sublingual. Before considering the morphogenesis it is necessary 
to give a brief description of their structure so as to establish their 
tonsillar character, which despite the application of this term, to them 
by Horr and OpPEL, might perhaps be questioned. 
Structure. In structure these tonsillar patches are similar. 
The connective tissue beneath the epithelium contains large numbers 
of cells with rather densely staining nuclei and scanty cytoplasm. 
They are usually closely packed. The overlying epithelium likewise 
is full of similar cells which are usually also closely packed. The 
epithelial cells themselves are not simply displaced but are present 
in the midst of the small (round) cells. They may be grouped 
as cuticular or surface cells forming a nearly or quite continuous 
surface layer, basal cells, next the basement membrane, and inter- 
1) The peculiar and marked assymmetry in the presence of the so-called 
Postbranchial body, may be recalled. . 
