■51 



soral seamen ionn \x ];),riciinc o* dernci of^cu v/uii im- 



mediatel;- v/all V imd lims malio the marf-inal coll 



of the sixLii grade t.lic ultiiiiatc one. Tiiic in a.pparoni,iy 

 LinalogouG to i-lie beh.pvior of aonie marginal cells of the 

 fifth grade in the leaf. 



Tiie Stalk. 



If Y/e follov; out the development of each of the six 

 sections of the different regions of the sporocarp, -e 

 marj "best begin v/itli the four or five pairs of segments of 

 the stalk. We shall find that these together produce at 

 maturity a structure much like the petiole of of the leaf, 

 of about half a millimeter in diameter end. from ten to 

 twenty millimeters in length. Each of the sections of 

 these segments cuts off plerome a.nd dermatogen cells, and 

 section I cuts off a soconL. portion of plerome as in 

 th.e laef , but only the plerome of sections I cmd III , 

 and usually only part oi section III (Fig. O), take 

 part in fonning the axial "bundle of the stalk. Th.e plerome 

 of t-lie other sections, together v/ith the periblem of all 

 the sections, developes into the tliicl: v.'..lled mesoph.yll 

 cells, if v/e may call them such, which give the mature 

 stalk its rigidity ana strength, anc^ some of vrliicJi grov/ 



