.008 



Fig. 22. B represents a loiigitndinal section of the stalks; 1, 2, 3, 4, 

 dotted (Incts; 5 and G spiral ducts; 4 and Care represented as being 

 choked up by means of budding spores, which were probably absorbed 

 as germinal matters and matured as represented into well-dellned cellu- 

 lar structure. Their enlargement by the mere i)rocess of budding would 

 tend not oidj- to fill up the whole air-space, but also to burst the cell- 

 Pi,^ 21, walls, destroying the functions 



°' * of the plant. U, budding-cells 



passing througli dotted duct- 

 cells. S.S.S.S, the newly dis- 

 covered fungi fruit, (oospores.) 

 Fig. 23. C represents a highly 

 magnified interior view of the 

 cells of the skin of an affected 

 potato, througli which a dark 

 jointed amber mycelium trav- 

 erses. I have not been able to 

 detect any form of mycelium 

 traversing the potato-cells, ex- 

 cept on tlie interior surface of 

 the skin; but judging from the 

 the habits o^ mycelium, I doubfc 

 not but that it may be found 

 traversing the interior of the 

 vascular bundles of potatoes 

 highly decayed, and as de- 

 scribed by Dr. PaVen. 

 Fig. 24. D exhibits the appearance of a section of potato showing the 

 st»rch-cells and vascular bundles, dotted ducts, and spiral forms inter- 

 mixed. The largest cells shown are more highly magnified to illustrate 

 their real character. They exhibit three belts or rings, and these rep- 

 resent three distinct cell-formations. The interior or third cell contains 

 the starch. r 



Fig. 25. E exhibits a section of a potato; g, the root-stem ; a, a, section 

 Fig. 22. of eyes; f, t, t exhibits the posi- 



tion of other eyes, but not in 

 section. It will be seen that 

 the inner markings exhibit a 

 series of central circular and 

 radiating lines leadingfrom and 

 returning to the root-branch g. 

 These lines represent the ar- 

 rangement of the vascular bun- 

 dles of the potato. When a 

 potato is cut in two sectionally, 

 lines will be exhibited as shown, 

 especially if a "pink-eye" po- 

 tato is used; and, if exposed to 

 the action of the air for a short 

 time, the nitrogenous matter in 

 the immediate vicinity of the 

 vascular bundles blackens. I 

 have stated that the starch is 

 inclosed in three cells. These 

 consist of, first, an outer cellulose, transparent cell; secondly, an opaque 

 nitrogenous cell; and, thirdly, of an inner cell, composed of very trans- 



