The Organism and Its Cells 157 



facts, the other a vaguely stated hypothesis. We further 

 saw that the secure generalization has two quite distinct 

 parts, the one stating that higher organisms are made up 

 of cells, the other stating certain cardinal facts about 

 the cell itself. But later examination fixed attention on the 

 fact that the theory as now held regards the cell itself as an 

 organism. In other words, the two essential components 

 of that part of the theory which is solidly grounded interpret 

 each other : By showing how the organism is made up, the 

 cells interpret the organism; and by showing wbat the cell 

 7.v /// itx fundamental attributes, the organism interprets the 

 cell. The cell is a "key" to the nature of the organism, but 

 not so in "last analysis" for, at least in equal measure, is 

 the organism a "key" to the cell. Or, if the idea of heredity 

 hi- introduced into the cell-theory, not more than half the 

 truth is contained in the statement that the cell "embraces 

 all hereditary qualities in its suhstance," for we have seen 

 that one of the corner-stones of the modern conception of 

 the cell, as laid down by Schult/e and Briicke, is that 

 the attrihntes of the organism belong to it also, not indeed 

 merely hidden "in its suhstance," but patent and observable. 

 If we restrict attention to the germ-cells and apply to 

 them the idea of hereditary qualities embraced in their sub- 

 stance, we are still bound, as consistent evolutionists, to ask 

 how the germ-cells came by these qualities. No answer is 

 forthcoming to this inquiry which does not essentially involve 

 the fact that the germ-cells received the qualities from the 

 p.-irent organisms. The interpretative relation between the 

 organism and its cells is one of strict reciprocality whether 

 the germ-cells or soma-cells be regarded, even in the broad 

 general terms of the cell-theory. The problem of the or- 

 ganism and its cells is the general form of the old special 

 problem of the hen and the egg. Which came first, runs the 

 familiar conundrum, the hen or the egg? Expressed ii? 

 scientific terms, the question is, which interprets or explains 



