VEGETABLE PHOSPHORESCENCE. 809 



reveals the spores which are the analogues of seed, although they pos- 

 sess neither their vestments nor organs, but are simple membranous 

 sacs (full of liquid), which germinate at some indefinite point of their 

 convex surface into a new plant like that which produced them. ■ 



A comparison of the condition of flowering plants and of the mosses 

 and fungi, during a phosphorescent display, will lead us to attribute 

 the appearance to similar action of vital forces, if we for a moment 

 review the processes by which these forces are accumulated. In the 

 growth of plants heat acts as a dynamic agent, which the germ of the 

 plant directs and uses. The first action of growth consists in the con- 

 version of the starch of the seed into a soluble form, and in chemically 

 combining the starch, sugar, oil, and albumen by fermentation into the 

 protoplasmic matter which supplies the material for the tissues of the 

 plant. The development of this protoplasm into organized tissue is 

 due to the inherent power of the germ, and marks the second stage of 

 progress. The only action of light is employed in producing higher 

 chemical combination ; heat acts as the constructive power. 



The process of growth does not absorb all the elaborated materials 

 provided, and an additional amount of heat or force is generated by 

 the decomposition or a "retrograde transformation" of these com^ 

 pounds. A much greater proportion, however, of the organized sub- 

 stances is stored up within the structure of the plant as a " reservoir 

 of reserved material," to meet the exhaustive process of flowering and 

 the maturing of fruit and seed. That these processes are sustained at 

 the expense of an extra amount of force, and by the decomposition of 

 their own products, is evident from the unusual jaroduction of carbonic 

 acid. The combination of carbon, oxygen, and hydrogen, in the build- 

 ing up of plants, is here reversed, and by a retrograde process heat is 

 set free, which we have seen is necessary for the elaboration of repro- 

 ductive agents. 



This appears to be precisely the same action which takes place in 

 the reproduction of fungoid plants and mosses. A corresponding con- 

 dition is shown by the rapid exhalation of carbonic acid ; indeed. Dr. 

 Carpenter asserts that a decomposition of a portion of the absorbed ma- 

 terial is the only conceivable source of the large quantity they are con- 

 stantly giving out, and ascribes the very rapid growth of these plants 

 to a " retrograde metamorphosis." The substances which enter into 

 the new growth are already prepared by the foster-plant, and we find 

 the parasite incapable of forming any new combination through the 

 agency of light. This necessarily awakens a doubt of any action re- 

 sulting from insolation or reflection in the cases of the liverworts or 

 mushrooms which have been referred to. 



The expression of light in flowering plants seems to be through the 

 medium of electricity, while in cryptogams it resembles the steady 

 glow of slow combustion. Iligli microscoiaic power may, however, re- 

 veal, as in some cases of animal phosphorescence, the sparkle and flash 



