Cell-Pedigrees 81 



individual cells for the whole organism. Or, in other 

 words, we should resolve the individual into its cells and 

 and their lineage. To this end the history of develop- 

 ment must furnish us the requisite facts which, however, 

 must include all forms of reproduction. 



The cellular pedigrees that are to be traced are of a 

 purely empirical nature. As Sachs has already empha- 

 sized, we have but to record the facts in as simple a group- 

 ing as possible, 1 and see what conclusions can be drawn 

 from them without resorting to any hypothesis. The 

 harvest will, to my mind, be much richer than would be 

 imagined at first glance. 



That the chief results of the consideration of cellular 

 pedigrees in both the plant and animal kingdoms will lead 

 to the same general conclusions, probably no one doubts at 

 present. But the conditions are quite different in the 

 plant world from those in the animal kingdom. The vari- 

 ous kinds of reproduction in the latter are not nearly 

 as numerous as in the former. A study of animals is 

 therefore much more exposed to the danger of one-sided 

 treatment than that of plants. Moreover, with the bot- 

 anist, the conviction that the anatomical and ontogenetic 

 investigation should always penetrate at least to the 

 individual cells has, under the influence of Mohl and 

 Nageli, for almost half a century, taken much deeper root. 

 Accordingly the ancestral sequence of by far the greatest 

 number of cells is, in innumerable cases, if not without 

 gaps, demonstrable with sufficient certainty at least in its 

 main lines. 



Therefore I shall be able to limit myself in this sec- 

 tion, without danger, to the cellular pedigrees of plants. 

 And this the more so, as the most important lines of 



1 Sachs, J. von. Vorlesungen uber Pflansenphysiologie. 1882. 



