MOLECULES AND STRUCTURE FORMATION 15 



as the extension in one or two dimensions becomes sufficiently large, 

 the long-range interactions at separated loci are quite different. 

 Thus, possibly an interaction pattern will emerge which we will 

 regard as being specific. 



Without proving the point, a great deal of evidence may be 

 selected from the behavior of biological systems which indicates 

 that long-range interactions may have elements of specificity. The 

 classical example is chromosome pairing, which has long excited 

 interest. I feel that the behavior of chromosomes during meiosis 

 suggests that a specific interaction occurs at the kinetochores, pro- 

 viding a primary point of orientation and possibly overcoming an 

 initial energy barrier to close approach. Thereafter, long-range in- 

 teractions might align homologous segments. Of course, a few of 

 the up-to-now invisible strands might provide condensed regions 

 over which a continuum of short-range interactions would be re- 

 sponsible for pairing. 



We appear to be dealing with fundamental types of forces of 

 interaction involving long- and short-range patterns of interacting 

 groups which can give rise to specificity of size, shape, and chemical 

 differentiation of interacting particles. From the large number of 

 possible combinations, the problem is to isolate and understand 

 those particularly important types which will further our under- 

 standing of the way in which structure is developed and of the rela- 

 tionships between structure and function. 



References 



Bennett, H. S. 1959. Structure of muscle cells. Revs. Modern Phijs. 31: 394-401. 

 Bernal, J. D. 1958. Structure arrangements of macromolecules. Discussions Fara- 

 day Soc. No. 25: 7-18. 

 Calvin, M. 1959. Energy reception and transfer in photosynthesis. Revs. Modern 



Phys. 31: 147. 

 Dole, M., and A. D. McLaren. 1947. The free energy, heat and entropy of sorption 



of water vapors by proteins and high polymers. /. Am. Chem. Soc. 69: 651-657. 

 Fernandez-Moran, H. 1959. Fine structure of biological lamellar systems. Revs. 



Modern Phys. 31: 319-330. 

 Hodge, A. J. 1959. Fibrous proteins of muscle. Revs. Modern Phys. 31: 409-425. 

 Kauzmann, W. 1959. Some factors in the interpretation of protein denaturation. 



Advances in Protein Chem. 14: 1-57. 

 KiRKWOOD, J. G. 1957. The forces between protein molecules in solution. /. Celhdar 



Comp. Physiol. 49 ( Suppl. 1 ) : 59-62. 

 Landsteiner, K. 1945. The Specificity of Serological Reactions. Rev. ed. Harvard 



Unifversity Press, Cambridge, Mass. 

 Langmuir, I., and V. J. Schaefer. 1943. Rates of evaporation of water through 



compressed monolayers on water. In F. R. Moulton (ed. ). Surface Chemistry. 



Publ. Am. Assoc. Advance. Sci. No. 21. Pp. 17-39. 



