Potentialities and ramifications of life under extreme environmental conditions.

A T A T I M E when man ventures his first tentative step into the wide spaces of the universe, it may be appropriate to take renewed stock of the most precious good we want to t ransfer to other worlds: life. We are curious to know how living matter will stand the shock of leaving its birthplace, the earth, and how it will cope with the possibility of facing its counterpart, another inhabited world. In preparation for this event we should scan the potentialities of life on our own planet as we find them today and as they have developed during the last billion years. We will have to supplement this knowledge by laboratory experiments probing fur-