Thus a departure from the terrestrial type in the envelope of gases covering a planet, instead of precluding life, would only tend to vary its manifestations.
After all, why should the intensity of the solar radiation upon Venus be regarded as inimical to life?
The sunbeams awaken life.
It is not impossible that relative nearness to the sun may be an advantage to Venus from the biologic point of view.

She gets less than one third as much heat as Mercury receives on the average, and she gets it with almost absolute uniformity.

At aphelion Mercury is about two and four tenths times hotter than Venus; then it rushes sunward, and within forty-four days becomes six times hotter than Venus.

In the meantime the temperature of the latter, while high as compared with the earth's, remains practically unchanged.

Not only may Mercury's temperature reach the destructive point, and thus be too high for organic life, but Mercury gets nothing with either moderation or constancy.