THE ANGIOLOGY, ANGIOGENESIS, AND ORGANOGENESIS 
OF THE SUBMAXILLARY GLAND. 
BY 
JOSEPH MARSHALL FLINT, M.D. 
From the Hearst Anatomical Laboratory of the University of California. 
WitnH 14 FIGURES. 
In a preliminary note’ on the blood-vessels of the submaxillary gland 
and their development, the writer outlined briefly the angiogenesis of the 
circulation, together with its arrangement and distribution in the adult 
organ. At the same time, attention was called to certain researches of 
Thoma concerning the principles involved in the development of blood- 
vessels and their application to the evolution of the circulation in highly 
organized glands. 'The following extracts from this paper may empha- 
size these points again briefly. 
“The well-known researches of Thoma on the histogenesis of the vas- 
cular system offer an explanation of some of the phenomena of vascular 
development, particularly to the relation between the velocity of the blood 
current and the size of the vessel that conducts it. The question of the 
ancestry of arteries and veins was solved by Thoma, who showed in chick 
embryos that originally they were always simple capillaries. Their 
subsequent transformation, according to this author, was due to their 
fortuitous location with reference to the primitive aortae, and the venous 
ostia of the heart. It has been shown that these facts apply to the vas- 
cular development in mammals as well as the chick, and for vascular 
systems developing in three dimensions, as well as those found in the 
area vasculosa where the vessels grow in two directions only. In consid- 
ering the problems of angiogenesis in mammals, it is apparent that 
Thoma’s histo-mechanical principles do not suffice to explain all the 
facts, nor do they even entirely accord with them. The statement that a 
new growth of vessels follows a rise of blood pressure in the capillary area 
must be considered only as an hypothesis and not a demonstrated fact, 
for this would make the vascular system the stimulus to the development 
of new cells, while there is considerable probability that it is the new cells 
1 Journal of Medical Research, Vol. VII, No. 4. 
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