April 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 401 



suggested ; " the male reproduction is associated with pre- 

 ponderating katabolism, and the female with relative ana- 

 bolism. In terms of this thesis, therefore, both primary and 

 secondary sexual characters express the fundamental physio- 

 logical bias characteristic of either sex " (p. 27). Later, on 

 p. 117, the following sentence occurs : " This much, however, 

 is distinctly maintained, that future developments of the 

 theory of sex can only differ in degree, not in kind from that 

 here suggested, inasmuch as the present theory is, for the first 

 time, an expression of the facts in terms which are agreed to 

 be fundamental in biology, those of the anabolism and 

 katabolism of protoplasm." 



On pages 122, 123, we find further: "Protoplasm is an 

 exceedingly complex and unstable substance or mixture of 

 substances, undergoing continual chemical change or meta- 

 bolism. On the one hand it is being continually recon- 

 structed by an income of nutritive material, which, at first 

 more or less simple, is worked up by a series of chemical 

 changes till it reaches the climax of complexity and in- 

 stability. These upbuilding, constructive, synthetic pro- 

 cesses are summed up in the phrase anabolism. But, 

 on the other hand, the protoplasm is continually, as it 

 ' lives,' breaking down into more and more stable com- 

 pounds, and finally into waste products. There is a dis- 

 ruptive, descending series of chemical changes known as 

 katabolism. Both constructive and disruptive changes occur 

 in manifold series. The same summit [i.e., of fully formed 

 protoplasm] may be gained or left by many different paths, 

 but at the same time, there is, as it were, a distinct water- 

 shed, — any change in the cell must tend to throw the 

 preponderance towards one side or the other. In a certain 

 sense, too, the processes of income and expenditure must 

 balance, but only to the usual extent, that expenditure must 

 not altogether outrun income, else the cell's capital of living 

 matter will be lost, — a fate which is often not successfully 

 avoided. The disruptive, or katabolic, or energy-expending 

 set of changes, may be obviously greater in one cell than in 

 another, in proportion to the constructive or anabolic pro- 

 cesses. Then we may shortly say that the one cell is more 

 katabolic than the other, or vice versa on the opposite 

 supposition." " Income too may continuously preponderate, 



