FUNCTION.] LORY ON THEIR RESPIRATION. 319 



be fixed in the vegetable, and to be replaced, at least in part, 

 by nitrogen disengaged by the mushroom. That when fresh 

 mushrooms remain some hours in an atmosphere of nitrogen, 

 they modify very slightly the nature of that gas. The sole 

 effect produced is confined to the disengagement of a small 

 quantity of carbonic acid, and sometimes to the absorption 

 of a very small quantity of nitrogen." 



The remarks of Lory upon this subject are, however, the 

 most recent and complete. The following is an extract from 

 his paper in the Annales des Sciences for Sept. 1847, p. 159, 

 on the respiration of Broomrapes (Orobanchacese.) 



The manner in which these plants behave with respect to 

 the air, or with respect to a mixture of air and carbonic acid, 

 is exactly that which might have been expected, considering 

 that there is no chlorophyll. 



In every stage of their vegetation, all the parts of these 

 plants, whether they are exposed to solar light, or whether 

 they are in the dark, absorb oxygen and give out carbonic 

 acid in its place. 



Experiments have been made by placing these plants, as 

 fresh as possible, in flasks filled with air, or with a known 

 mixture of air and carbonic acid, closed by tightly-fitting 

 corks, and having their necks plunged in water or mercury. 

 In every case, the flask was closed so tightly that no gas could 

 escape by expanding, and no liquid could enter it when the 

 volume of the gas diminished. In these circumstances, no 

 sensible quantity of carbonic acid can be lost by being dis- 

 solved, whilst if the mouth of the flask had not been corked, 

 there would have been a considerable loss of this gas, and the 

 result would have been sensibly erroneous. 



In more than thirty experiments made during the months 

 of May and June, the temperature and light, the composition 

 of the atmosphere of the flask, the ratio of the volume of the 

 plant to that of the flask, were all varied as much as possible : 

 and lastly, plants were taken at different stages of growth, 

 from the moment when the stem rose above the soil, until the 

 flowering was completely over. 



Each experiment lasted about thirty-six hours ; the flask 

 was exposed either to diffused light, or to the full rays of the 



