The Biological Problem of To-day: Preformation Or Epigenesis? The Basis of a Theory of Organic Development

As may be seen in his essays, _On Life and Death_, _On the Duration of Life_, etc., Weismann believes himself to have established a fundamental distinction between unicellular a...

Now that criticism of the germplasm theory has given us a bias in the right direction, it is necessary to map out more clearly the path along which solution of the problem may b...

What is development? Does it imply preformation or epigenesis? This perplexing question of biology has reappeared recently as a problem of the day. Of late years there have been...