. Beihefte zum Botanischen Centralblatt. Botany. ITolm, Soino now nnatoinical for certiiiu Gr?iminoae. 103 Ch ii r a c tc r i st i c ö o {' thc double p a r(;n c h y in a - s Ii «a t Ii. In a traiisversc sectioii of i\w, leaf oT tlie grasH ahove nained thc inestome-bundles are sccn to be Burrouiuled by onc or, some- timcs, two layers of palisades, arrangcd radially around tliem. These palisades border inwards on a closed shcath of thin-walled cells lilled with Chlorophyll. This encloses another shcath of largcr cells, with slightly thickened walls and with thc same Con- tents as th
. Beihefte zum Botanischen Centralblatt. Botany. ITolm, Soino now nnatoinical for certiiiu Gr?iminoae. 103 Ch ii r a c tc r i st i c ö o {' thc double p a r(;n c h y in a - s Ii «a t Ii. In a traiisversc sectioii of i\w, leaf oT tlie grasH ahove nained thc inestome-bundles are sccn to be Burrouiuled by onc or, some- timcs, two layers of palisades, arrangcd radially around tliem. These palisades border inwards on a closed shcath of thin-walled cells lilled with Chlorophyll. This encloses another shcath of largcr cells, with slightly thickened walls and with thc same Con- tents as thc outer one (S in figure 1). Inside thcse shcaths are the leptome and liadrome of thc same structure and disposition characteristic of the Giamineae in general. The mcstome-bundles are, thus, surrounded by two very distinct sheaths (P and S in üg. 1), the cells of which are round in outline as seen in trans- verse sections, and they both contain Chlorophyll, which as to V. s Fig. 1. Ti ansverse section of a small mestome-bundle of ^riV/tZa fasciculata; P = the outermost parenebyma-sheath; S = the inner parenchyma- sheath; L = leptome; M = thick-walled mestome-parenehyma; V = Vessels. 840 X natural size. The chlorophyll-grains have been omitted. Fig. 2. Longitudinal section of the double parenchyma-sheath; letters as above. 744 X nat. size. color and relative size of grains, does not difFer from that, con- tained in the palisades. Viewed in longitudinal section (fig. 2) both sheaths appear to be parenchymatic, somewhat stretched, but with almost horizontal cross-walls. In this particular the inner sheath departs from the structure characteristic of a mestome- sheath, as this term has been applied by Prof. Schwendener to certain internal sheaths, which occur in a number of Gramineae, Moreover the testing with concentrated sulphuric acid did not ^ive the result, usually obtained in cases where a mestome- sheath is developed. While thus the mestome-bundles of Aristida 7*. Please
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