Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 63. (Budapest 1971)
Kováts, D.: Some histological observations on Lihospermum purpureo-coeruleum L. seedlings
1 Fig. 4. Areal ratio of xylem and pith in mm 2 , and their quotient, in cross sections. 1. Radicula with compact xylem cylinder. 2. Hypocotyl at commencement of pith tissue organization. 3. Developed hypocotyl. 4. Epicotyl with continuous xylem ring. 5. Epicotyl, with disjoining xylem ring at various levels and in cross sections. It is worthy of note that at the lower level of the hypocotyl —where the pith is already forming —the xylem occupies a larger area in cross section than in the root. The difference (quotient) between the two areas is the greatest at this level. At higher hypocotyl levels, the increase of the pith surface concurs with the decrease of the xylem area: the two cross section surface values approach each other and the quotient strongly decreases. Near the insertional points of the cotyledons, the value of the xylem area sinks below that measured in the root. At a lower epicotyl level, where a continuous xylem ring still exsits, the areas of the xylem and pith tissues are nearly equal, and their
