Science  29 Nov 1907:
Vol. 26, Issue 674, pp. 744-749
DOI: 10.1126/science.26.674.744


The following facts are those which are put forth through paleontological observation, for verification by others:

1. That many origins of new characters are through some internal action in heredity.

2. That many important adaptive characters arise determinately, definitely, but by extremely slow stages.

3. That degrees of similarity in such origins correspond with degrees of kinship. 4. That degrees of kinship also affect to a certain extent, but not absolutely the time of appearance, or the time of the origin, or the rate of evolution.

5. That such origins find expression not sponta. neously, or irrespective of conditions, or from purely internal mechanical causes, but through some entirely unknown and at present inconceivable relation to ontogeny (habit and use), to environment (external conditions), and to selection.

6. That if such origins do spring from internal hereditary principles, as they appear to do in many eases, slow origins (mutations of de Vries) may be simply

due to the same law operating with a different velocity