46 
There is every reason to suppose, for example, that the action of light 
is not the same under all the conditions of temperature which ob- 
tained during these experiments. Here again, however. we are con- 
fronted by the unknown; because, in order to draw from these 
researches the consequences which might flow from them it would be 
necessary to know precisely the thermic conditions favorable to the 
germination of each species. Unfortunately this is a very important 
gap to be still filled up, as the work accomplished in this direction 
gives only approximate results limited to a very small number of 
different kinds of seeds. On the other hand, looking to facts of 
another order, mentioned further on in this work, we think that we 
may be allowed to suppose that the influence of light can only be 
favorable to germination when it acts at temperatures below that 
which is most favorable to germination. A considerable number of 
observations already cited would seem to be in accord with this view 
of the subject. But unfortunately the many contradictions that we 
observed in our results do not allow us to accept this opinion as based 
upon a solid foundation. 
Pauchon then goes on as follows: 
Another reason, however, induces me to admit, only with many 
reserves, the results of experiments whose critical epoch is the visible 
development of the embryo. A method based on this special observa- 
tion does not appear to me capable of furnishing a really scientific 
basis for the determination of the question before us. The process of 
germination is not, in reality, as simple a phenomenon as the greater 
pumber of botanists, perhaps too easily, take for granted. Its com- 
plexity is even so great that one can not judge of the actual develop- 
ment of the germ of the plant and of the degree of its physiological 
activity by the external characters observable by the eye, such as the 
bursting of the spermoderm and the more or less rapid protrusion 
of the radicle. I do not hesitate to say, according to observations 
frequently repeated, that this is an empirical process and entirely 
deceptive in the particular case that we are dealing with. Although 
it may be capable of furnishing valuable results when we wish to 
judge of the influence of some one of the fundamental conditions of 
germination, it becomes utterly insufficient when it is a question of 
observing the more delicate and fugitive influences, such as that of 
light. T hav e, in fact, in the course of chemical researches, given 1n 
the next chapter, demonstrated that for the same stage of apparent 
development the absorption of oxygen by the seeds in the process of 
germination varies to a large extent with the temperature, and has 
no relation to the external growth of the embryo. It is, however, 
not surprising that the development of the embryo continues in the 
interior of the seed for a much longer time in one seed than in 
another of identical appearance; the unknown and variable relation 
between the reserved nutrition and the rudimentary vegetable is 
probably the explanation of these hitherto unexplained peculiarities. 
Although the researches given in this chapter do not give any post- 
tive result on the subject of 1 my work, I have preserved them and pub- 
