xix.] CLOVER DODDER. 123 



until they reach, the central pith FF, as illustrated. 

 The suckers could not penetrate the clover stem were it 

 not for the woody skeleton belonging to each sucker ; 

 this atom of hard pointed woody material pierces the stem 

 like a small thorn. Hairs of the clover stem are shown 

 at GG. The connection of a sucker of dodder with the 

 clover stem, as seen under the microscope, is illustrated, 

 farther enlarged to fifty diameters, in Fig. 54. The outer 

 pallisade-like cells of the dodder are shown at AA, AA. 

 The woody cylinder at BBB, the loose cellular tissue at 

 CCC, and the point of a sucker, inserted in a clover 

 stem, at D. The centre of the clover stem is shown by the 

 pith -cells at E, the cells of the clover bark at FF, and 

 two fibro-vascular bundles at GG. The parasitic life of 

 clover dodder commences with the insertion of the first 

 sucker into the host plant. When the pith is reached by 

 the suckers pushing themselves in between the cells of 

 the stem of the host, the cellular tissue of the dodder 

 comes into close contact with the living cells of the 

 clover, and the result is, the vital juices elaborated 

 by the clover pass through the cell walls of the clover 

 into the cells of the dodder, and so the sap of the clover 

 feeds the parasite by transfusion. The dodder grows 

 with such extraordinary rapidity when it has once fixed 

 on clover, and it produces so many branches and brach- 

 lets, with such a vast number of suckers, that the growth 

 of the parasite generally far exceeds that of the host. 

 The consequence is, the dodder completely drains out 

 the elaborated juices of the clover and kills it by ex- 

 haustion. The destruction of the clover is also hastened 

 by the great weight of the accumulated masses of en- 

 tangled dodder ; for one commonly sees the clover quite 

 prostrate on the ground, whilst most of the thickly- 

 matted dodder growth is on the top. The profuse 

 growth of dodder in some clover fields was well illus- 

 trated by a correspondent of the Agricultural Gazette, who 

 wrote on 9th July 1870, p. 941, that his men had found 



