208 Conm-d — Fnsciation in 



I have yet to find plants of sweet potato entirel}' free from 

 fasciation, though they have been carefully looked for ; doubt- 

 less, however, many such exist. On counting the stems just 

 as they lay on the ground, I found, in a poor location as to 

 soil and exposure, 12 per cent of them abnormal, in good rich 

 soil 18 per cent. Counting the tips or apices just as they 

 came on poor and good soil, the former gave 20 per cent, the 

 latter 54 per cent of abnormal growths. The stems show a 

 smaller percentage, because even the fasciated ones are normal 

 in appearance toward their bases. 



RiNG-FASCi.\Tiox. — Along with the ordinary fasciations there 

 appear in the sweet potato, as in other fasciated races, various 

 peculiar malformations, such as split or dichotomous branch- 

 ing, split fasciations, and especially that remarkable condition 

 which has been termed " ring-fasciation." Of this last I 

 would make especial mention, as it occurs in about one-half 

 of one per cent of the abnormal stems. 



The ring-fasciated stem is, like the flat fasciated, perfectly 

 normal in appearance toward the root. Then, tracing it out- 

 ward, it increases in diameter to three or four times the normal 

 (one-half inch more or less), its leaves become irregularly placed, 

 and finally the rounded growing apex is seen to be a hollow 

 ring, instead of a knob of embryonic tissue (Fig. 6). In 

 short, the ring-fasciation is a hollow stem, open at the grow- 

 ing tip. The hollow portion ma}- include as much as two 

 or three feet of the terminal part of a branch, and the cavity 

 may reach a quarter of an inch in diameter. On splitting open 

 such a hollow stem, small leaves and adventitious roots are 

 found in the cavity. These leaves develop acropetally, those 

 farthest from the open apex being oldest ; but of course they 

 never attain to any considerable size, nor can they become 

 actively functional. They are more numerous toward the 

 stem tip than lower down. In the case of cuttings planted in 

 earth, roots spring from the inside as well as from the outside 



