49 
served can also be accounted for by attributing them to certain dif- 
ferences in the atmospheric conditions. 
(6) The more considerable absorption of oxygen by seeds under 
the influence of light explains the fact that asparagine (the medium 
for the conveyance of the reserved albuminous substances in the ger- 
mination of leguminous plants) only disappears in plants exposed 
to the light and continues present in those raised in the dark. The 
comparative researches of Pfeffer (1872) upon the chemical com- 
position of asparagine and other substances showed that asparagine 
is poorer in carbon and in hydrogen and richer in oxygen than 
fegumine and other albuminoids. The transformation of Tegumine 
into asparagine is accompanied by the absorption of a certain quan- 
tity of oxygen. On the other hand, it is effected only by the influ- 
ence of light, the reason being that light increases the quantity of 
oxygen absorbed, and therefore exerts only an indirect influence on 
this change, as had already been surmised even when we were not 
acquainted with the reasons. 
(7) Other new and important conclusions become apparent from 
these experiments and those which follow, and although they have 
no direct connection with the subject of my work I think it will be 
well to designate them briefly. 
The quantity of oxygen absorbed in a certain space of time by a 
seed in process of germination varies very considerably according to 
the temperature ; it increases with it, as has been already proved in 
treating of the respiration of plants in the dark. The general results 
of my experiments, and particularly of Nos. 9 and 10, leave no doubt 
of this fact. We can therefore easily understand what errors have 
been committed by those experimentalists who have given calcula- 
tions of this absorption of oxygen by certain seeds without taking 
into consideration the conditions as to temperature. Their figures 
have no value whatever, particularly in view of a fact stated by me 
several times already, viz, that the quantity of oxygen absorbed ‘by a 
seed is not at all in proportion to its apparent development, but, on 
the contrary, undergoes considerable variation, depending upon the 
influence of the external agents affecting the phenomenon. Accord- 
ing to my observations, this quantity may vary as two to one, or even 
more, in two plants of identically the same weight, but placed in dif- 
ferent thermic conditions from the commencement of their germina- 
tion to the emerging of the rootlet. From this point of view, then, 
the plant acts like a complete organism, its respiratory action being 
accelerated or retarded always, however, within physiological limits, 
like those of an animal under the influence of certain exterior changes. 
Having thus shown that germinating seeds absorb more oxygen in 
the hght than in darkness, Pauchon conducted some experiments to 
determine the ratio between the oxygen and the carbonic acid, and 
draws the following conclusions (see page 182 of his work) : 
Experiments Nos. 3 and 4 have a real va alue for the solution of the 
problem brought forward in this part of my work. As to the partial 
results given by experiments Nos. 1, 2, and 5, their accur acy can not 
be doubted; therefore I shall make use of them as confirmatory docu- 
ments. I must repeat that the numbers used for the proportions of 
2667—05 m——4 
