1353 
striking still, when compared with bloodplasm instead of the total 
blood. 
As regards the technique to obtain cerebro-spinal liquid from rabbits, we 
obtained it by puncturing (with a glass capillary tube); the ligament connecting 
occiput and atlas after this had first been exposed by cutting the skin and 
preparing the muscles of the neck under local anaesthesia (without adrenalin); 
consequently obtaining the liquid of the fourth ventricle. The animals can 
bear this quite well. 
We have embodied the results in tables III and IV. 
In examining these tables we must bear in mind that a compar- 
ison of cerebro-spinal liquid and bloodplasm under physiological 
conditions is much more troublesome than in the case of chamber- 
liquid; the operation generally lasts half an hour, and, when the 
liquid can be obtained, distinct hyperglycaemia has occurred in the 
blood in the mean time (this appears from the tables). Hence in the 
values found for cerebro-spinal liquid, which in themselves are not 
abnormally low (average 0.18°/, in table III) there is already a 
certain amount owing to the increase of the quantity of blood-sugar. 
The value of this quantity cannot be given however, as we do not 
know the rapidity of diffusion here. The physiological difference 
with the bloodsugar-percentage is, therefore, fairly certainly smaller 
than that which we find if we compare with the plasm, taken simul- 
taneously (column 3). But it is most certainly larger than would 
appear from a comparison with the plasm at the beginning of the 
experiment (column 1). By means of a larger number of experiments 
and by causing the operation to last as short as possible we may 
probably obtain more accurate data here. We shall, besides, obtain 
an insight into the rapidity of diffusion from an investigation of the 
speed with which adrenalin-hyperglycaemia manifests itself in the 
cerebro-spinal liquid and also of the degree of this manifestation. 
Onr next experiments will lie in that direction ’). 
On the strength of table IV we may accept as certain that the 
sugar-percentage in cerebro-spinal liquid is considerably lower than 
it is in the chamber-liquid which was investigated simultaneously 
(cf. columns 3 and 4). 
So we see here two “ultra-filtrates’ with diverging sugar-percent- 
ages. Are we to think here of an “active” stopping of glucose by 
the plexus chorioideus? It seems to us that we need not call in 
the aid of a similar force, but that the cause should rather be 
1) The results of these have been mentioned in the more detailed publication 
in the “Biochemische Zeitschrift”. 123. 190. 1921. 
