LATENT LIFE—BECQUEREL. 541 
pared in the same manner, but closed at one of its extremities, 
indicated under what conditions and at what rate the gas passed 
through the tezuments. 
In this way I was able to determine that the tegument of most of 
the seeds of Leguminose, such as that of the lupine and honeylocust, 
when it reached a certain degree of natural desiccation,! proved itself 
to be for two years impermeable to air in all its parts, even in those 
containing the hilum and the micropyle. The teguments of these 
seeds do not permit gases to pass through them under the laws of 
diffusion except when they are moistened with water. 
On the other hand, desiccated embryos of these same seeds act like 
porous bodies. Gases pass through them according to the laws of 
effusion. The tegument of the same species is equally impermeable 
to liquids, such as absolute alcohol, ether, and as Wk which 
readily penetrate the embryos after Hcecudention 
These results apply not only to the seeds of many species of the 
family Leguminose, but likewise to those of certain Crucifere, 
Malvacee, cee Linacee, and Cistacee. They justify the 
reservations that I had made concerning the greater part of the 
experiments of my predecessors, for, in showing that the embryos 
protected by their impermeable teguments were not submitted to the 
action of the media employed, they nullify in part the deductions 
that had been drawn from them to explain the nature of latent life. 
I was thus led to repeat on seeds with the permeable tegument 
either perforated or removed, the experiments of some of my prede- 
cessors. I thereupon ascertained that, contrary to their assertions, 
absolute alcohol, chloroform, and ether, instead of preserving the 
embryos of seeds, kill them when no longer protected by their tegu- 
ments. On the other hand, the fact of the impermeability of their 
tegument rendered very improbable the interpretation that had been 
placed upon the gaseous exchanges of certain seeds. 
With seeds of lupine, peas, castor beans, and beans, taking into 
account the réle of their tegument, I repeated the experiments of 
Van Tieghem and Gaston Bonnier. Several comparable lots were 
prepared, some containing only decorticated seeds, others consisting 
only of the teguments of these seeds, and finally some seeds protected 
by their teguments. All these lots were placed in the confined and 
dry atmosphere of tubes inverted upon mercury, some placed in full 
light, others in darkness. 
Six months later, having made analyses of these confined atmos- 
pheres, I found that the gaseous exchanges had been greater in the 
light, and that the isolated teguments of the seeds had absorbed 
more oxygen and given off more carbon dioxide than the embryos. 
1 Degree of desiccation which is normally attained in the ordinary conditions of conservation of seeds. 
