MORPHOLOGY, GENETICS AND BREEDING 37 



1 . The abrupt out-swelling of the collar. 



2. The sudden appearance of the intact epidermis of the .hypocotyl at 

 the collar. 



3. The transition from radial to collateral arrangement of the vascular 

 strands. 



4. The immediate appearance of tannin cells associated with the col- 

 lateral bundles. 



HYPOCOTYL 



The hypocotyl in the seedling stage is very succulent, white, and 

 smooth. The central stele may be quite green even though the hypocotyl is 



y.. 



y 



Figure 6. — Young peanut hypocotyl, cross section midway between collar and 

 cotyledons. Note the intact epidermis, wide cortex, stele with collateral vascular 

 traces, and central pith, (ajter Yarbrough, 76.) 



