I 



Or-Gk. 



Th3 outermost corners of the pentagons 

 v;il] probably not b 2 formed by the gamma carbon 

 atoms as in the case of hexagons, but th3re are 

 substances such as cystine, 



S-GH2.CPim2.COOH 



S-CH2.CHl^^o.C00H, 



among the decomposition products of proteins 

 which suggest other types of structures for 

 connecting together adjacent polypeptide spirals. 



The presence of a peripheral region 

 structurally different from the interior also 

 seems to account for the tendency of unicellular 

 organisms to divide. Except in rare cases of 

 coincidence, different molecular structures 

 would occupy different amounts of space, so that 

 as the organism increases in 1 ength there will 

 be a point reached when the expansive force of 

 th :5 more bulky structure will tear apart the 

 less bulky structure, so as to cause the organism 

 to divide into two halves. Most bacteria have 

 rounded ends, which appears to indicate that the 

 interior structure is more bulky than the peri- 

 pheral structure, but there ar 2 a few species 

 with concave ends in which the reverse condition 

 appears to exist. 



