276 PHYSIOLOGY. BOOK IT. 
When a germinating seed has acquired the necessary 
degree of heat and moisture, it abstracts from the air a por- 
tion of its oxygen, and gives out an equal quantity of carbonic 
acid gas ; but, as one volume of the latter gas equals one 
volume of oxygen, it is evii^ent that the seed is, in this way, 
deprived of a part of its carbon. Some changes take place in 
the albumen and cotyledons; and, finally, the faecula that 
they contained is replaced by saccharine matter. In like 
manner a flower, while expanding, robs the air of oxygen, and 
gives out an equal volume of carbonic acid ; and a sugary 
matter is also formed, apparently at the expense of the faecula 
of the disk or petals. 
The quantity of oxygen converted into carbonic acid in 
germination is, cceteris paribus^ in proportion to the weight of 
the seed ; but some seeds absorb more than others. Theodore 
de Saussure has shown that exactly the same phenomenon 
occurs in flowers. 
Heat is a consequence of germination ; the temperature is 
also augmented during flowering, as has been proved by 
Theodore de Saussure in the Arum, the gourd, the Bignonia 
radicans, Polyanthes tuberosa, and others. 
The greater part of the saccharine matter produced during 
germination is absorbed by the radicle, and transmitted to the 
first bud of the young plant. Dunal is of opinion that the 
sugar of the nectary and petals is in like manner conveyed 
to the anthers and young ovules, and that the free liquid 
honey which exists in such abundance in many flowers, is a 
secretion of superabundant fluid ; it can be taken away, as is 
well known, without injury to the flower. 
This opinion will probably be considered the better founded, 
if it can be shown that the disengagement of caloric and de- 
struction of oxygen are in direct relation to the developement 
of the glandular disk, and also are most considerable at the 
time when the functions of the anthers are most actively 
performed. 
In no plants, perhaps, is the glandular disk more developed 
than in Arums ; and it is here that the most remarkable degree 
of developement of caloric has been observed. Senebier found 
that the bulb of a thermometer, applied to the surface of the 
