546 TRANSACTIONS. OP SECTION I. 



phagocytosis in a similar way. So we made experiments with chloroform, 

 chloral, camphor, benzine, turpentine, and balsamum peruvianum. All these 

 substances promoted phagocytosis to a very considerable extent. For instance, 

 chloroform was seen to accelerate phagocytosis even in a concentration of 1 to 

 5,000,000. In a concentration of 1 to 500,000 the increase of phagocytosis 

 amounted to 43 per cent. In stronger solutions this value was smaller, and the 

 stronger the solution the more the accelerating effect diminished. This must 

 be attributed to a second factor coming into play, viz., paralysis of the proto- 

 plasm-motion, which factor manifests itself but little in a very weak solution. 

 Benzine was found to have the most favourable effect on phagocytosis in a 

 dilution of 1 to 100,000. Generally this concentration depended upon the 

 relative solubility of the substance in fat and water (Teilungscoefficient). 



Our results correspond entirely to those observed by /. Loeb in the artificial 

 fertilisation of the eggs of the sea-urchin and the starfish. By allowing, namely, 

 substances, dissolving fat, to act upon these eggs he could effect the development 

 of these into larvae. However, it must be noticed that other substances promoting 

 this development, such as digitaline, strophantine, saponine, did not affect phago- 

 cytosis. We only observed an acceleration by substances soluble in fats. 



Probably we have to do here with a phenomenon of general bearing. Even 

 plant-cells were seen to conduct themselves in the same way. So we succeeded 

 in promoting the germinating of wheat grains by small quantities of chloroform. 

 Evidently we must think here of a greater activity of cell-division, caused by 

 softening of the lipoid membrane. 



2. On the Physiology of Gas Production in connection with the Gas Bladders 

 of Teleostean Fish. By W. N. F. Woodland, D.Sc. 



The gaseous contents of the bladders of Teleostei are found on analysis to 

 consist for the most part of a mixture of oxygen, nitrogen, and carbon dioxide, 

 these constituents of the mixture being present in very different proportions in 

 different species of fish. According to the most recent and best established view 

 of the subject, these three gases are extracted from the blood stream and 

 transferred to the bladder cavity by the squamous cells composing the lining 

 epithelium of the bladder. In the case of those gases which are only present 

 in small quantity in the bladder, their presence may be accounted for by the 

 assumption of a simple process of diffusion from the blood stream, but when 

 a particular gas is present in the bladder in such quantity as to exert a pressure 

 many times greater than that exerted by the same gas in the blood, it is 

 necessary to assume that the cells lining the bladder exert a pumping action. 

 E.g. , the bladders of many freshwater (Cyprinidse, e.g.) and some marine 

 (Exocoztus volitans, the flying-fish, e.g.) fish contain as much as 94 per cent. 

 of nitrogen, exerting a partial pressure many atmospheres greater than the 

 pressure of the nitrogen present in the blood. Bladders containing nitrogen 

 and carbon dioxide to the practical exclusion of oxygen secrete these gases by 

 means of the ordinary cells lining the bladder cavity, but bladders containing 

 a considerable percentage of oxygen (and in some the contained gas consists 

 of nearly pure oxygen) always possess a special development of the lining 

 epithelium termed the gas or oxygen gland. This gas gland consists essentially 

 of a local proliferation (folded or massive in type and very varied in form) 

 of the enlarged and columnarised epithelial cells, each of which is in contact 

 at one end with the thin endothelium of a blood capillary and at the other 

 with the bladder cavity or a duct leading into it. In constant association with 

 the gas gland is the rete mirabile duplex, a structure which is of as much 

 importance for the filling of the bladder with oxygen as the gas gland itself. 

 The rete mirabile consists of the intimate intermingling of the two sets of 

 fine capillaries formed by the subdivision in the same region of the body 

 of the artery and vein which supply the gas gland — the artery breaks up into 

 a bunch of hundreds of fine capillaries carrying blood of course to the gland, 

 and closely intermingled with these are the equally numerous and fine 

 capillaries of the vein returning the blood from the gas gland. This rete 

 mirabile may be bipolar — i.e., the arterial capillaries at the end of the rete 

 next the gland may unite into a few large vessels before again subdividing 



