18 
INDUCTION, DEVELOPMENT, AND HERITABILITY OF FASCIATIONS. 
DESCRIPTION OF PLATE IV. 
Semt-diagrammatic transverse sections of stems; size reduced to two-sevenths of given 
magnifications. 
SERIES 1. O. dzennis. Successive stages in the development of a groove-fasciation 
Medullary parenchyma, mm, region of cambium, c,; region of outer phloem and 
stereome ring, f/,,; region of the inner phloem, f/,,; xylem, xy, cortex, ca, 
epidermis, ¢J. X 44. 
a. Initial appearance of meristem, f2. 
5. Appearance of supplementary meristems, ,, #,, position of groove, g; thick- 
walled parenchyma surrounding meristems, A. 
c. Differentiation of secondary bundles, 4,, d,, d,, etc.; callus, c/. 
@,. Gradual enlargement and increase of secondary bundles; region of outer phloem 
and of stereome ring, ZA, ; region ofinner phloem, p/,,; xylem, xy, , cambium, c,. 
é. Union of secondary bundles with primary ring. 
Ff. Last stage before complete fusion with primary ring. 
SERIES 2. O. cruciata. Development of a fasciation associated with a cylindrical pro- 
tuberance. Lettering as before. x 18. 
a. Initial appearance of meristem, 7. 
6. Differentiation of secondary bundle-ring, 4,, in the pith. 
c. Connection of secondary bundle-ring with the primary ring. 
ad. Fusion of the same. 
e. Beginning of formation of protuberance at &. 
Jf. Protuberance cut off, 2. 
SuRIES 3. O. dzennzs. Development of ring-fasciation. X 25. 
a. Appearance of a single meristem, 7». 
6. Development of supplementary meristems, 7z,, 7,, m2; , etc. 
c. Differentiation of meristems into ring of secondary bundle-groups, 5,, d,, 45, etc. 
ad. Appearance of lysigenous cavity, ca. 
e. Gradual fusion of secondary bundle-groups. Inner epidermis, ¢f,, inner cortex, 
cx,; outer phloem of secondary ring, #%;,; inner phloem of secondary ring, 
phy; xviem, xy,; pith, Ae. 
‘f. Break in side of ring, making a flat fasciation. 
SERIES 4. O. btennis. Four stages of thé development of a specimen intermediate 
between Series 1 and 3. 4a corresponds with 3c. The secondary bundle-ring 
arises in the middle and passes to the side, where it fuses with the primary 
ring. X 20. 
