Nachdruck verboten. 
On some Experimental Tests of Recent Views concerning the 
Physiology of Gas Production in Teleostean Fishes. 
By W. N. F. WoonLanp, 
The Zoological Department, University College, London. 
With 3 Figures. 
Introductory. 
In a paper “On the Structure and Function of the Gas Glands 
and Retia Mirabilia associated with the Gas Bladder of some 
Teleostean Fishes’, recently published in the Proceedings of the 
Zoological Society of London (June, 1911), I have given (in Part 1) 
a detailed account of the structure of the gas-producing mechanism 
associated with the gas bladder of a certain number of teleosts, and 
(in Part 2) a sketch of recent views, including a few original suggestions, 
concerning the mode of function of this mechanism. In order that 
the contents of the present paper may prove intelligible to the reader, 
it will here be necessary to recapitulate briefly the main conclusions 
stated in the memoir just mentioned. In those fishes which inhabit deep 
water and are in the habit of changing their depth to a considerable 
extent, oxygen is the gas employed for the inflation (when the fish 
sinks and thereby experiences greater pressure) and deflation (when 
the fish rises and thereby experiences a diminution of pressure) of 
the bladder rendered necessary by the change of level. Oxygen is 
employed for this purpose in preference to nitrogen (the other principal 
gas usually present in the bladder) owing to the relatively large 
quantity present in the blood and its ready absorptibility into the 
same medium. Deflation is effected in physoclistous teleosts by means 
of the “oval”, the oxygen passing through this specialized permeable 
area of the bladder wall into the blood. Inflation is, according to all 
accounts, effected by the gas- or oxygen gland —a usually local pro- 
liferation of the lining epithelium of the bladder, the squamous cells 
of which have become enlarged and columnarized, and so arranged 
that each cell 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 
Anat. Anz, Bd. 40. Aufsätze, 15 
