430 The Submaxillary Gland 
capillary plexus extends around the duct from the point where they are 
situated. Each successive ramification remains practically a terminal 
system, although occasional anastomoses are found running from the 
vessels accompanying one branch of the duct to those about another. 
These communications, however, are usually venous and not arterial, 
although connections between vessels of the latter type are occasionally 
found. The capillary plexus embracing the terminal buds is now much 
finer and more definitely organized than in the earlier stages. Arterioles 
run along with the terminal ducts and suddenly break up into an irregu- 
lar, fine plexus composed of small polygonal meshes which mount up 
Fig. 6. Submaxillary gland of pig’s embryo 12 centimeters long. Same method 
of preparation as Fig. 5. x 10 diameters. In this specimen only the arteries 
accompanying the ducts and the terminal alveolar plexus are visible. 
over the summit of the alveoli and are collected into venules which 
return to the point of junction of the ducts and alveoli, and there unite 
into little terminal veins that accompany the ultimate arterioles. At 
this period an occasional branch from one of the terminal arteries 
passes out from between the buds and joins the smail plexus that is 
being formed on the capsule of the gland. As yet septal arteries are 
not found. Fig. 6 shows an injected silver preparation of a pig at 
this stage. Except in certain points the mass has not passed over into 
the veins, for the most part leaving the arteries and capillary plexus 
around the alveoli the single visible portion of the vascular system. The 
greater regularity of the alveolar plexus is now clearly shown. 
