274 George 8S. Huntington and Charles F. W. McClure. 
(a) Cephalic extension of the dorsal veno-lymphatic channel 
to union with the cephalic division of the ventral plexus. 
(b) Caudal growth of part of the cephalic division of the 
ventral plexus until union with the dorsal plexus has been effected. 
(c) Development of intermediate detached areas of veno-lym- 
phatie character, which, isolated at first, subsequently unite 
with both the dorsal veno-lymphatic plexus and with the cephalic 
division of the ventral plexus, and thus effect the junction of the 
secondary arch with the primary veno-lymphatic elements. 
Series 118, 10°" Embryo 
Reconstruction of left side 
) 
Lateral aspect, fig. 48 
This embryo is characterized by multiple discrete veno-lym- 
phatie development along the entire dorso-lateral circumference 
of the preeardinal and promontory, resulting in the formation of 
numerous early communication between the veno-lymphatic 
plexuses and the main venous channel. It also shows marked 
displacement of a portion of the caudal division of the ventral 
veno-lymphatic plexus from the dorsal to the lateral aspect of the 
- promontory. 
The Caudal Division of the Ventral Veno-lymphatic Plexus. 
This division of the ventral plexus is composed of a number of 
elements, with separate entrances into the precardinal and 
promontory. : 
These elements group themselves into two main areas, anterior 
and posterior, each of which contains subordinate components. 
1. Anterior Area of the caudal division of the ventral plexus. 
The anterior portion of the caudal division of the ventral plexus 
is separated, as in the preceding series 112, into two parallel ele- 
ments, a ventral and a dorsal (fig. 48, V and D), which are joined 
by a narrow curved piece. ‘The former element (V), representing 
