ARRANGEMENT OF IJNT AND FUZZ. 23 



Lucas, in eastern Guatemala, between Cajabon and Sonahu, shows 

 the most extreme specialization of the two kinds of hairs on the 

 seed. The lower half of the seed is without lint, but has a dense, 

 velvety covering of bright-green fuzz. The upper half of the seed 

 produces lint but no fuzz. 



In addition to the positional relation of the fuzz and lint there are 

 also differences in the lengths of the lint fibers on different parts of 

 the seed. Some varieties of Upland cotton have a strong tendency 

 to have the fibers of the upper part of the seed distinctly longer than 

 those of the lower part, so that when the lint is parted and combed 

 out from the seed a "butterfly" outline is formed. The butterfly 

 tendency is undesirable because inequality in the lengths of the fibers 

 lessens the commercial value of the cotton for spinning purposes. 

 Even when the long fibers are not all restricted to the upper part of 

 the seed, the lower part may show an evident preponderance of 

 shorter fibers. 



ARRANGEMENT OF THE ROOTS AND UNDERGROUND SHOOTS. 



The central stalk of the cotton plant extends into the ground to 

 form the taproot. The lateral roots arise in four rows from four 

 shallow vertical grooves, one on each side of the taproot. The 

 regularity of arrangement is often obscured by the bending and 

 twisting of the taproot, as well as by the fact that the lateral roots 

 take different directions and develop very unequally. But most plants 

 show definite indications of an arrangement of the roots in rows, 

 and in occasional individuals, where all the roots happen to project 

 at right angles, the four-ranked character of the root system is very 

 plain, even in old plants. (Fig. 9.) 



In addition to the various kinds of buds and branches already 

 described, the cotton plant is able to produce underground shoots 

 from the same grooves as the roots. The underground shoots have 

 at first a rounded or irregular form, Hke root nodules or galls, and 

 may represent modified root primordia. The nodules grow to 

 various sizes, sometimes attaining a diameter of nearly an inch before 

 sho^\dng the le&fy bud that develops into a vegetative branch. The 

 similarity to crown galls may prove interesting and even worthy of 

 study from the standpoint of pathological tissues. 



Subterranean shoots seem to be developed much more freely in 

 the Egyptian cotton than in Upland varieties. They seemed to be 

 generally distributed over a whole field of several acres of Egj^ptian 

 cotton at Bard, Cal., where nearly all of the plants were killed down 

 to the ground in the winter of 1910-11. The roots of all the plants 



