AO DfO 01 



CORN POLLEN 

 SUSPENSION 



' I ' ' I ' M ' ' I ' 



520 550 580 610 



;)(nn>.) 



Fig. 3. Difference spectrum (at — 190°C) representing the difference in absorption 

 between oxidized and dithionite-reduced com pollen suspensions. 



655 



558 



520 



1^ 



550 



I I I I I 



■ 580 



OX-HOONO/DPNH 



L^L- T 



OX-CN/DPNH 



520 



I ' ' I ' • I ' 



550 580 610 



A (nip) 



Fig. 4. Difference spectra (at — 190^C) obtained from a corn pollen homogenate. 

 The spectra represent the difference in absorption between oxidized homogenates 

 and homogenates reduced with dithionite (left), reduced with DPNH in the 

 presence of HOQNO (upper right) and DPNH reduced in the presence of cyanide 

 (lower right). Note the difference in scale between the spectrum on the left and 

 those on the right. Fresh pollen was supplied by Mr. D. B. Walden of Cornell 

 University, Ithaca, N.Y. 



