24 



ARRANGEMENT OF PARTS IN THE COTTON PLANT. 



that were dug up in different parts of the field were found to be alive 

 and showed in May, 1911, many different stages of development of 



the subterranean shoots. Sev- 

 eral of the lower leaves of such 

 branches were small and distorted, 

 but normal leaves were produced 

 on shoots that had emerged from 

 the ground. 



In cases where the plants had 

 not been killed too far down, new 

 shoots had been formed at the 

 axils of the cotyledons and no 

 subterranean shoots or nodules 

 were found. If the buds in the 

 axils of the cotyledons had de- 

 veloped into Umbs in the previous 

 year, new adventitious buds were 

 produced from the swollen bases 

 of the hmbs. The branches from 

 such buds were very small and 

 slender at first, quite unhke the 

 large, fleshy excrescences that gave 

 rise to the underground shoots. 

 The lower part of the stalk, rep- 

 resenting the hypocotyl of the 

 seedling, between the cotyledons 

 and the surface of the ground, 

 seems to have no power of pro- 

 ducing adventitious buds. Nor 

 did any of the nodules appear 

 upon the lateral roots of any of 

 the plants that were dug up. 

 They seem to be entirely confined 

 to the same lines or grooves which 

 give rise to the normal lateral 

 roots, and often show very clearly 

 the same arrangement in four 

 vertical rows. (Fig. 9.) 



CONCLUSIONS. 



Fig. 9.— Taproot of Egyptian cotton, showing the 

 arrangement of lateral roots and underground 

 shoots. 



Plants are compound organisms 

 built up by many units of struc- 

 ture, the internodes or metamers. In studpng the anatomy of a 

 plant like cotton, two principal classes of differences may be taken 



