Jour. Sc f. Co//. Vo/. XX/. Art. /O. PI. /. 



/'/>/. /. 



/'■/>/. 1'. 



u - 



io 



\t/f//,ji/iu/i . 

 /■'/;/. /. Fiiiri/ i'icw. />>/. 1', /i'/r-A- i'/'-H'. 



