70 The Cephalic Veins and Sinuses of Reptiles 
tissue is very important in this form which is known for its habit of 
burying itself in loose sand or earth (Boettger, 79). 
In Chameleon vulgaris the spongy tissue is somewhat equally dis- 
tributed around the nasal opening and the following movements have 
been observed: (a) Elevation and. depression of the margin of the 
nasal opening; (b) changes in the form of the opening, due to unequal 
expansion of different parts of the spongy tissue; (c) waves of expansion 
from within outward. These sometimes surrounded the entire opening or 
they were limited to one side of the opening. 
The resemblance of this spongy tissue of the nasal vestibule of the 
lizard to the erectile tissue of the reproductive organs has been remarked 
by Leydig, 72, p. 92, and Born, 79, both of whom, however, failed to 
report the presence of smooth muscle fibers. A preliminary note calling 
attention to these fibers was published by the writer of this paper in 97. 
The smooth muscle fibers have also been observed by Osawa, 98, pp. 304, 
348, in Hatteria. 
It is worthy of note in this connection that a spongy tissue similar to 
that of the nasal vestibule of the lizard occurs in the region of the inferior 
turbinate bone of mammals. Such tissue has been observed by Isch 
Wall, 87, in the mole, armadillo, pig, rat, and cat, while its presence in 
man has long been known to anatomists. 
d. DISTENSION OF THE SINUS PALATINUS AND SMALLER SINUSES 
OF THE HEAD. 
The phenomena above described are the most conspicuous effects which 
follow the obstruction of the vena jugularis interna and the elevation of 
blood-pressure in the head. Somewhat similar effects must, however, 
be produced in the sinus palatinus and in the numerous smaller sinuses 
and veins of the head. Evidence of the gradual distension of the super- 
ficial veins, such as the vena mandibularis, may be readily seen during 
the first stage. The high blood-pressure of the second stage also shows 
its characteristic effects. In an anterior direction a pulse-like wave runs 
through the vena maxillaris and causes distension of the sinus vestibuli 
nasi. Other vessels of this region are undoubtedly affected in the same 
way. The compression of the anterior part of the vena jugularis interna 
. by the m. protrusor oculi must produce a similar, though less pronounced 
wave in the postorbital region, but owing to unfavorable conditions, 
especially because of the muscular movements which occur at this time, 
I have been unable to discover a pulse in the veins of that region. ‘This 
may be explained in part, also, by the action of the bucco-pharyngeal 
