200 



AGRICULTURAL REPORT. 



ti»e. i'-A'ct Ibat iLk-oi; \<i.sca!iii' huiidles I'oiiii ii coiiiplcte .splicic, at 



(►f jibou( IVoui one to two cightby of au iucli below the surface, euv 



the whole interior portion of Fig. oti. 



the i)Otato, and connecting' 



witli the outer surface at every 



eye. If fuugoid spawn {my- 



celium) or spores are contained 



in the S])iral or dotted ducts 



which form tiiese bundles 



they will be visible, as the 



acid will not affe(jt either the 



ducts themselves or the fun- 



a depth 

 eloping' 



gus. 



Fig'. 35. C represents a high- 

 ly magnified interior view of 

 the cells of the skiu of au 

 affected potato, traversed by 

 a dark jointed amber myceli- 

 um. I have not been able to 

 detect any form of mycelium 

 traversing the potato-cells, 

 except on the interior surface 

 of the skin ; but judging from the habits of mycelium, I doubt not that 

 it may be found traversing the interior of the vascular bundles of po- 

 tatoes highly decayed, as described by Dr. Payen. 



Fig. 36" D exhibits the appearance of a section of a potato showing 

 the starch-cells and vascular bundles, dotted ducts, and spiral ducts 

 intermixed. The largest cells shown are very highly magnified, in order 

 to exhibit their real structiu'e. The pentagonal lines, which will be 

 observed inclosing the starch granules, represent a section of three dis- 

 tinct cell-waUs, one within the other. The interior, or third cell, con- 

 tains the starch. 



Fig. 37 exhibits a section of a potato ; g, the root-stem ; a a, sections 

 of eyes - ttt exhibits the position of other eyes, but not in section. It 

 will be seen that the inner Fig. 37. 



markings exhibit a series of 

 central circular and radiating 

 lines leading from and return- 

 ing to the root-branch g. 

 These lines represent the ar- 

 rangement of the vascular 

 bundles of the potato. When 

 a potato is cut in two section- 

 ally, lines will be exhibited as 

 shown, especially if a " pink- 

 eye " potato is used ; and, if 

 exposed to the action of the 

 air for a short time, the nitro- 

 genous matter in the imme- 

 diate vicinity of the vascular 

 bundles blackens. I have 

 stated that the starch is in- 

 closed in three cells. They 

 consist of, first, an outer 

 cellulose transparent cell ; secondly, an opaque nitrogenous cell or 

 lining; and thirdly, an inner cell, composed of very transparent cellu- 



