232 DR. W. N. F. WOODLAND ON THE 



rete to the gland the toxin effects by a process of haemolysis the 

 partial or total disintegration of a cei'tain proportion of erythi-o- 

 cytes, the cytoplasm and oxyhjemoglobin pigment of each being 

 scattered in the plasma, the former giving rise to the masses of 

 granular mattei- so largely present in the blood returned from the 

 bladder and the latter becoming dissolved in the plasma. 



Is there any evidence of this process actually taking place ? 

 In reply to this question I am able to cite one fact, ah^eady stated 

 on page 219 in Part I., which I think constitvites strong evidence in 

 the affirmative. It is evident that if this process takes place 

 then we may expect to find at the proximal pole of the rete, i. e. 

 the pole remote from the gas gland, large quantities of granvilar 

 matter (resulting from the erythrocytolysis above described) 

 present in the venous capillaries but little or none in the arterial, 

 and that towards the dit^tal pole of tiie rete (the toxin, on the 

 hypothesis, having had time to diffi'use from the venous capillaries 

 and influence the arterial blood) granular debris will also appear 

 in the arteries. Careful examination of the rete mirabile asso- 

 ciated with active glands has convinced me that this inferred 

 distribution of the granular matter in the rete capillaries is a fact. 

 Figure 32 (PI. lY.) represents a section taken across the proximal 

 pole of the rete and shows the absence of the erythrocytolytic 

 granules in the arteries ; a section across the distal end of the rete, 

 on the other hand, shows that haemolysis of the arterial blood has 

 commenced, erythrocytolytic granules being present. 



Oppel (56) puts a question which will be asked by many other 

 critics of the foregoing theory of " red body " physiology. Why, 

 he asks, is it at all necessary for the erythrocytes to be broken up 

 in order that oxygen may be supplied to the cells of the gas gland ? 

 In other words, if, as we know is the ciise, the blood readily gives 

 up its oxygen to supply the ordinary tissues of the body, where 

 is the necessity for the manufactvire of a special toxic substance 

 in order to effect this same liberation of oxygen in the case of the 

 gas gland ? I am not aware that Jaeger or any other author has 

 given a definite answer to this question, but a consideration of 

 the facts will soon supply one. In the first place, it is evident 

 that the cells of the gas gland stand in a very different relation to 

 the oxygen of the blood as compared with that of ordinary tissue 

 cells, since whereas the latter are deficient in oxygen and require 

 it solely for purposes of metabolism, the former are already 

 saturated Avith oxygen aud only lay hold of it in order to con- 

 centrate it and pump it into the bladder ; in other words, the 

 cells of the gas gland require to get a very efliectvial "grip" on 

 the oxygen which the tissue cells do not *. Secondly, realization 

 of the conditions obtaining in the normal supply of oxygen by 

 the blood to the tissues will enable us to understand the necessity 

 for a toxin. The combination of oxygen with the haemoglobin 



* This necessity for the gas gland cells to be in the closest contact with the bicod 

 is possibly accountable for the presence of the intracellular capillaries already 

 describeil, perhaps also for the intracellular lumina as conveyors of exuded plasma 

 into tlw celi-substance. The same phenomena are met with in the cells of the 

 liver — an organ which also requires close contact with the blood—, the canaliculi 

 vepvescntiiig the intracellular channels. 



