H. M. KALCKAR 



Questioning the value of the speculations and considerations 

 put forward in this short essay might well be justified. The mesomeric 

 description of phenomena like reproduction and catalysis is, admittedly, 

 sheer speculation. Yet, it is a kind of speculation which may prove 

 to be highly constructive, inasmuch as phenomena are introduced 

 which are within the realm of experiments. The studies of Theorell, 

 Pauling, Coryell and Michaelis and his group, on the paramagnetic 

 susceptibility of biologically important substances point out the direc- 

 tion of future research. An adaptation of these methods on a micro 

 scale (10) might very likely pave the way for an experimental attack 

 on problems like catalysis and auto catalysis. 



References 



(1) Delbrlick, M., Cold Spring Harbor Symposia Quant. Biol., 9, 122 (1941). 



(2) Delbriick, M., "Problems of Modern Biology in Relation to Atom 

 Physics." Lectures delivered at Vanderbilt University, 1944. 



(3) Eyring, H., Chem. Revs., 17, 65 (1935). 



(4) Haas, E., Biochem. Z, 290, 291 (1937). 



(5) Jordan, P., Naturwissenschajten, 32, 20 (1944). 



(6) Kalckar, H. M., Ann. N. T. Acad. Sci., 45, 395 (1944). 



(7) Lewis, G. N., and Kasha, M., J. Am. Chem. Sac, 66, 2100 (1944). 



(8) Michaelis, L., and Schubert, M. P., Chem. Revs., 22, 437 (1938). 



(9) Pauling, L., The Nature oj the Chemical Bond. Cornell Univ. Press, Ithaca, 

 1939. 



(10) Theorell, H., Arkiv Kemi Mineral. Geol., A16, Art. I, 1 (1942). 



(11) Waelsch, H., private communication. 



240 



