Ill] OF AUTOCATALYSIS 257 



synthesis of nuclear protoplasm, or nuclein; for he remarked that, 

 as in an autocatalysed chemical reaction the rate of synthesis 

 increases during the initial stage of cell-division in proportion to the 

 amount of nuclear matter already there. In other words, one of 

 the products of the reaction, i.e. one of the constituents of the 

 nucleus, accelerates the production of nuclear from cytoplasmic 

 material. To take one more instance, Blackman said, in the address 

 already quoted, that "the botanists (or the zoologists) speak of 

 growth, attribute it to a specific power of protoplasm for assimila- 

 tion, and leave it alone as a fundamental phenomenon; but they 

 are much concerned as to the distribution of new growth in innu- 

 merable specifically distinct forms. While the chemist, on the 

 other hand, recognises it as a famihar phenomenon, and refers it to 

 the same category as his other known examples of autocatalysis." 



Later on, Brailsford Robertson upheld the autocatalytic theory 

 with skill and learning*; and knowing well that growth was no 

 simple solitary chemical reaction, he thought that behind it lay some 

 one master-reaction, essentially autocatalytic, by which protoplasmic 

 synthesis was effected or controlled. He adduced at least one 

 curious case, in the growth and multiphcation of the Infusoria, 

 which can hardly be described otherwise than as catalytic. Two 

 minute individuals (of Enchelys or Colpodiuyn) kept in the same drop 

 of water, so enhance each other's rate of asexual reproduction that 

 it may be many times as great when two are together as when one 

 is alone; the phenomenon has been called allelocatalysis. When a 

 single infusorian is isolated, it multiplies the quicker the smaller the 

 drop it is in — a further proof or indication that something is being 

 given oif, in this instance by the living cells, which hastens growth 

 and reproduction. But even the ordinary multiplication of a 

 bacterium, which doubles its numbers every few minutes till (were 

 it not for hmiting factors) those numbers would be all but incal- 

 culable in a day, looks like and has been cited as a simple but most 

 striking instance of the potentiahties of protoplasmic catalysis. 



It is not necessary for us to pursue this subject much further. 



* T. B. Robertson, The Chemical Basis of Growth and Senescence, 1923; and 

 earlier papers. Cf. his Multiplication of isolated infusoria, Biochem. Journ. xv, 

 pp. 598-611, 1921; cf. Journ. Physiol, lvi, pp. 404-412, 1921; R. A. Peters, 

 Substances needed for the growth of. . .Colpodiy,m, Journ. Physiol, lv, p. 1, 1921. 



