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hand he describes the vena femoralis as lying “in a prismatic space’, 
bounded by fasciae, and in which a negative pressure is supposed 
to arise with contraction of the M. sartorius through tension of the 
fascia lata. On the other hand in the same demonstration the cir- 
cumstance that the vena poplitea is kept open on leaving Hunters 
canal, is correlated with an arcus tendineus stretched by adductor 
fibres and grown into one with the vascular sheath. Then again, 
according to the writer the same principle holds for the fossa 
poplitea and for the fossa Scarpae. On the other hand again, the 
arcus tendineus of the M. Soleus is supposed to act in the same 
way for the vasa tibialia, passing below il, as above the M. adductor 
magnus for the vv. poplitea. : 
It is obvious that two different principles have been mixed np 
here by the writer. Moreover the question arises whether these two 
mechanisms to keep the venae open actually coincide. 
Now, | think, some objections may at once be raised against 
FRANSEN’S interpretation of the effect of a negative pressure in the 
fossa Scarpae and the same applies of course to the fossa poplitea. 
In the first place for a negative pressure-action to arise, as FRANSEN 
conceives it, it is necessary for the “space” containing the vessels, 
to be closed hermetically. It is both groundless and improbable to 
suppose that such a closure should be brought about by the fasciae. 
In the second place that “space” round the vessels is quite filled 
with more or less closely woven connective, as is easily made out 
by the study of transverse sections. And though the intercellular, 
interfibullar groundsubstance of that connective tissue may be humid, 
it would require special experimentation to see whether any negative 
pressure could be propagated through such a colloidal medium. 
In the third place, granting these two conditions to be fulfilled 
and the influence upon the vena as supposed by FRANSEN to really 
exist, two other conditions have to be satisfied for an effect on the 
bloodstream im the vena: 
a. change of place or form of the vena as a whole on one side 
should be excluded. A ‘prismatic space’ could not satisfy this 
condition 
6. Since we cannot conceive of a sucking pump without valves, 
there must needs be at least one valve proximad from Hyrrr’s 
suction-apparatus. Now it is remarkable that on page 26 of his 
thesis FRANSEN says, in agreement with Dergert: “No valves occur 
(or if any, the are insufficient) in the vena fomoralis beyond the 
outlet of the vena saphena magna.” 
So it seems to me that FRANSEN’s view is open to controversy on 
