212 Conard — Fasciation in 



became weaker below, some of the bundles, the writer states, 

 changing their orientation of phloem and xylem and continu- 

 ing in the lower normal portion of the spadix as ordinary 

 medullary bundles. Since in the sweet potato and in the case 

 next to be considered, the internal bundle system vanishes 

 entirely, it is especially curious to find some of its members 

 in Pepcromia becoming parts of the normal structure. The 

 medullary bundles found in this plant are not present in the 

 other two. This makes the investigation of Pepcromia more 

 difficult, so that it seems reasonable to suggest that even here 

 the internal system may have vanished, some of the medullary 

 bundles being distributed inward into the space thus left vacant. 



The second case of ring-fasciation also came from de Vries, 

 whose careful investigations have most contributed to make 

 teratology a scientific study. The plant was Veronica longifolia. 

 Fasciated material of this species was sent to de Vries in 

 1887, and by skillful propagation and selection the stock 

 yielded in 1893 several hundreds of fasciated flower-trusses; 

 two of these were ring-fasciated (4). The specimens were 

 investigated by A. Nessler (17) in 1894. One was 17 mm. 

 long, the cavity being 2 mm. in diameter, the tube spreading 

 into three lobes at top ; the other was divided above on one 

 side, and continued as a flat fasciation. Internally the struc- 

 ture agreed exactly with that described in the sweet potato, 

 except that the spiral trachese of the internal bundle system 

 were the elements persisting farthest down into the pith. In 

 the sweet potato, the phlcem elements were observed lowest 

 down. 



Another stem of the same origin, investigated by Nessler, 

 contained a ring of vascular bundles in the pith which united 

 with the normal ring above but vanished below as in the other 

 cases. The only external sign of this was an increase in the 

 diameter of the stem. Was this a case of arrested ring-fas- 

 ciation ? 



