there arc only ten primary ai- cunalc foiT.iod in tlu; leal, 

 as in floured l:).- BiGclioff {*?:., VIII , 1 ) and Cainp- 

 bell ('^Mj, XV , 10 ). The partitions like the sections 

 from v/hich they arise are thicker, and seem to ho m-^c.\\ more 

 irrefT.lar in both size aiid posit ioii, than in I.'iarsilia. 

 The trachea formed in section II oi' eacli se^TOcnt is liere 

 less prominent from its size than in the petiole of ^'lar - 

 silia. 



The Sporocarp. 



Tlie bean shaped sporocarps of f.feirsilia qiiadrifolia 

 are most often home in paii-s, tlic stalks of the tvo ap- 

 parently uniting belov/ to foi-Tn a common stalk, wliich. joins 

 the petiole O- the fertile leaf on its iiiner side near 

 tlie base. Occasionally only one sporocarp is foiind on a 

 leaf, or there may be tv/o v/ith their stalks inserted sep- 

 arately on the petiole, and tliese mp.y be several milli- 

 meters apart at maturity. A^f^ain, more rarely still, tliere 

 may be three or foiir sporocarps, all witli a common stalk, 

 or one may arise separately from the petiole v.diile tlie 

 others arc joined to it by a common stalk. In the }'0unp;er 

 stages, v/hen the sporoc;:rps are not yet lialf grov.Ti, it is 

 usually foimd that the smaller or younger one of a pair 

 or of three, is boi-ne on tlie side of the stalk toward the 



