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Henry L. Bruner 
middle lne to join the vena trachealis sinistra. Lateral to the base of 
the tongue the vena buccalis forms a connection with the vena bucco- 
mandibularis, which places it in communication with the vena mandibu- 
laris externa. 
b. VENA TRACHEALIS DEXTRA. 
(stds a ext, Rigs 32) 
The vena trachealis dextra is formed by the union of the vena buccalis 
dextra and vena lingualis, which meet above the anterior hyoid cornu, 
close to the hyoid body. ‘The short trunk runs caudad and meets the 
vena trachealis sinistra near the caudal end of the -hyoid bone. 
The vena buccalis dextra resembles in every respect the corresponding 
vein of the other side and requires no special description. 
The vena lingualis is formed at the base of the tongue, by the union of 
the vene linguales, dorsalis and ventralis. The trunk vein runs along 
the ventral side of the hyoid bone, then bends to the right and joins the 
vena buecalis dextra, as above described. In front of this junction the 
vena lnguals receives small tributaries from the larynx, trachea, and 
hyoglossus muscle. The larger tributaries of the vena lingualis are (1) 
the vena lingualis dorsalis (v. 1. d., Text Fig. 3), which drains the tip 
and the dorsal part of the tongue, (2) vena lingualis ventralis (v. Ll. v., 
Text Fig. 3), which collects blood from the deeper part of the tongue, 
the frenulum, and the median part of the floor of the mouth near the 
symphysis of the lower jaw. 
At the rostral end of the hyoid bone the vena lingualis ventralis re- 
ceives a cutaneous vein, vena mentalis, which begins near the symphysis 
of the jaw and runs backward between the skin and the cerato-mandibu- 
lar muscles. 
ec. DEVELOPMENT OF THE VENA TRACHEALIS. 
The unsymmetrical arrangement which is shown by the vena trachealis 
and its tributaries in the adult lizard, is preceded in early embryonic 
stages by paired vene tracheales, which discharge, each into the vena 
jugularis interna of its own side. This condition persists, according to 
Grosser and Brezina, 95, in an embryo of Lacerta with a head 4.1 mm. 
long, although the left vein is already somewhat smaller than the right. 
In the ensuing stages a connection is established between the two veins 
anteriorly and the posterior part of the left vein undergoes degeneration, 
