LATENT LIFE—BECQUEREL. 539 
82 days in a dry vacuum, and in free air for 30 minutes at a temper- 
ature of 100° C. 
Some time later, Paul Bert in his researches upon the inherent 
vitality of tissues, corroborated this point of view by some interesting 
experiments. He showed that rats’ tails dried for eight days, then 
kept for two hours in a temperature of 99° C., and grafted four days 
afterwards, resumed their vitality at the end of a month. About 
two years later, Claude Bernard, in his admirable lessons on the 
phenomena of life common to plants and animals, resumed the study 
of reviviscence and applied it to the vegetable kingdom. 
In order to characterize the state of repose in which the seeds 
exist before germinating, he coined the term “‘latent life’? and he 
gave us the following theory: 
The latent life of seeds is potential. It exists ready to manifest itself if suitable 
exterior conditions are supplied, but there is not the least manifestation if these con- 
ditions are lacking. 
It would be wrong to think that the seed, in this case, possesses a life so attenuated 
that its manifestations escape observation because of the very degree of this attenuation. 
That is true neither in theory nor in fact. In theory, we know that life results from 
the coalition of two factors—the one external, derived from a cosmic world; the other 
internal, derived from the organism. 
It is a coordination impossible to separate, and we should understand that in the 
absence of one of these factors the being could not live. It no more lives when the 
factors exist under unsatisfactory conditions than when they exist alone. Heat, 
humidity, and air do not constitute life; no more does the organism. In fact, we see 
some seeds preserved for years and for prolonged periods which after such long inaction, 
can germinate and produce a new plant. If they had a sluggish life, that ought to 
exhaust it. But it is not exhausted. 
From the moment that it was proposed, this conception of latent 
life has had many supporters who have strengthened it by the estab- 
lishment of new facts. Thus the resistance of seeds, of spores of 
bacteria and mushrooms to the action of a vacuum, of irrespirable 
gases such as nitrogen, carbon dioxide, carbon monoxide, and 
chlorine, the conservation of the germinative power in liquids such as 
mercury, alcohol, ether, and chloroform, as shown through numerous 
experiments by Giglioli, Detmer, Romane, de Candolle, Kochs, 
Jodin, Ewart, Kurzvelly, Maquenne, to cite only the principal 
authors, demonstrate in an apparently indisputable manner the 
reality of suspended life. 
In spite of these facts, however, other physiologists have neverthe- 
less continued to defend a theory directly opposed to it; that of the 
continuity of the vital phenomena, a doctrine according to which 
latent life is but a life relaxed. . 
Among the most eminent supporters of this view we may cite Van 
Tieghem and Gaston Bonnier, whose researches on the latent life of 
seeds have become classic. 'These scientists having allowed separate 
lots of seeds to remain two years in confined air and in carbon dioxide, 
