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



origin of gas as bubbles in the cytoplasm of the gas gland cells, 

 we as certainly disagree with the interpretation they put upon 

 this phenomenon, viz. that the gas is produced as the result of 

 the actual chemical decomposition of the cytoplasm. Like Jaeger 

 we have found no evidence of that peculiar cell-disintegration 

 which is supposed by Nusbaum & Reis to be the histological 

 expression of the chemical decomposition of the cell. It is true, 

 as Jaeger admits, that in the cells of active gas glands the 

 cytoplasm (not the nucleus, which remains normal) often assumes 

 a " hfird -worked "appearance — the cytoplasm looks "stringy" and 

 contains numerous empty spaces — and considering that the 

 process of continuous pumping of gas into the bladder must be 

 exceedingly arduous, this is not surprising. It is also true, 

 though not admitted by Jaeger, tbat the expulsion of bubbles 

 from the cell into the bladder involves, to a considerable extent, 

 waste of cell-substance. Each bubble, as already mentioned, 

 possesses a wall of cytoplasm, and on the bursting of the bubble 

 in the bladder lumen or gland duct, this wall, of course, breaks 

 down and contributes to the mass of granular matter found in the 

 bladder lumen and gland ducts. It must be confessed, therefore, 

 that cell-disintegration occurs to a considerable extent and is 

 associated with the production of bubbles of gas, but this 

 mechanical disintegration of cell-substance is quite another thing 

 from the hypothetical chemical decomposition of cell-substance 

 postulated by Nusbaum & Reis (see Appendix B). Jaeger 

 criticises this hypothesis of ISru.sbaum & Reis in a very effectual 

 manner. He fii'st of all points out that it is impossible to regard 

 the epithelium of the gas gland as analogous in its mode of 

 working to a sebaceous gland, since the cells of the sebaceous 

 gland decompose in order to produce a highly- complex substance 

 chemically different from the substances supplied to them by the 

 blood, whereas the cells of the gas gland give rise to the most 

 simple of substances, viz. the gaseous elements oxygen and 

 nitrogen which are supplied to them ready-made. In other 

 words, the production of oxygen and nitrogen, unlike the secretion 

 of the sebaceous gland, requires ho elaborate cell-metabolism, and 

 there is therefore no reason for the gas gland cell-decomposition 

 which Nusbaum & Reis affirm *. Further, according to Nusbaum 

 & Reis, the blood corpuscles in breaking up supply the gas gland 

 cells with oxygen for the decomposition of their substance, from 



* We may, indeed, comisave the process of gas-production with another process 

 familiar to the present writer, in which a simple substance is also supplied to the 

 cell and again liberated by that cell though in a difterent form, viz the deposition of 

 calcareous spicules in various invertebrate groups. Calcareous spicules have, like 

 gas bubbles, been regarded by some investigators as resulting from the actual trans- 

 formation of cell-substance, but this view is not held by any modern zoologist. The 

 spicule-secrcting cell is now regarded as a mechanism for abstracting the dissolved 

 calcareous matter from the sea-water and of redepositing it, mixed with a variable 

 minute amount of organic substance, in a crystalline form, the aggregate of calcite 

 crystals constituting the spiciile. The work of the cell in this case is simply the 

 abstraction and recrystallization of the dissolved calcareous salts — there is no question 

 of cell-decomposition. The mode of working of the kidney cell may also be compared 

 in this connection. 



