PROCEEDINGS OF THE AMERICAN ACADEMY 



wo 2 = wo 2 



o 

 wo 2 = wo 2 



1 I 



o 

 wo 2 = wo 2 



1 I 



o 



wo 2 = wo 2 



1 I 

 O 



wo 2 = wo 2 



o o 



wo 2 = wo 2 



o o 



wo 2 = wo 2 



o o 



wo 2 = wo 2 



o o 



n 



o o 



HO-W0 2 - W0 2 -OH 



HO-W0 2 — W0 2 -OH 



HO-W0 2 — W0 2 -OH 

 I I 



o 



1 I 



3(HO) = PO-0-OP=(OH) a 



