176 T. Holm — Studies in the Cyperacece. 



tiated as " grains," and by its more intense green color. This 

 is the sheath which Haberlandt has mentioned as characteristic 

 of Papyrus cieuta, and which Rikli has so excellently described 

 after he detected it in other genera of the Scirpoidece. While 

 Duval-Jouve was well aware of the radial arrangement of the 

 palisade cells around the mestome-bundles in several species of 

 Cyperus, as his illustrations show, he does not seem to have 

 noticed the inner sheath, the " chlorophyll-sheath," at least he 

 does not figure or mention it.* 



While the chlorophyll-sheath is completely closed in all the 

 peripherical mestome-bundles, which, as stated above, are also 

 surrounded by an uninterrupted sheath of palisade-cells, it 

 merely occurs around the leptome in the mestome-bundles of 

 the inner band. We remember from the above that these 

 bundles are not surrounded by palisade-cells excepting on their 

 leptome-side, and it seems as if the development of the inner, 

 " the chlorophyll-sheath," is somewhat depending on the pres- 

 ence of palisade-cells ; at least the chlorophyll-sheath is strictly 

 confined to that part of the mestome, which is, also, sur- 

 rounded by palisade-cells. These structural peculiarities : the 

 development of the assimilating tissue into sheaths around the 

 mestome-bundles and accompanied by an inner chlorophyll- 

 bearing sheath, does not seem to depend upon any particular 

 mode of growth, if we merely consider the stem. We have 

 noticed this same structure in cylindrical as well as in triangu- 

 lar stems of certain genera of Cyperacece, in erect as well as 

 in curved, besides in the singular flattened stems of Fimoris- 

 tylis autumnahs R. et S. It seems, therefore, hardly probable 

 that the presence of these sheaths depends on any particular 



* Professor "Warming (Halofyt-Studier, p. 259) insists that Duval-Jouve, not 

 Haberlandt, should have credit for the discovery of these peculiar sheaths, stat- 

 ing that Duval-Jouve in the year 1875 described and illustrated these as charac- 

 teristic of a number of Graminece. However, the chlorophyll-sheath, the one 

 that lies close up to the mestome-sheath and which borders immediately on the 

 leptome and hadrome, has so far never been observed in any of the Graminece. 

 What Duval-Jouve describes and figures is a sheath of palisade-ceils, a paren- 

 chyma-sheath, that surrounds the mestome-bundles and finally a mestome-sheath, 

 inside of the parenchyma-sheath. But in none of his descriptions or in his illus- 

 trations has Duval-Jouve hinted at the existence of a chlorophyll-sheath inside 

 of the mestome-sheath. It is true, that the mestome-bundles in the leaves of 

 several Graminece, for instance Cynodon, exhibits three sheaths: one of radially 

 arranged palisade-cells, a second the ordinary parenchyma-sheath, and a third the 

 mestome-sheath, but none of these correspond with the sheath which Haber- 

 landt detected inside of the mestome-sheath in certain Cyperece, and which Rikli 

 has lately discussed in his very important paper on this subject. Furthermore 

 Professor Warming states, that although Duval-Jouve did mention and figure the 

 palisade-sheath as characteristic of several French Cyperus-species and Galilea, 

 he, nevertheless, seemed to have overlooked the inner one " the chlorophyll- 

 sheath " of Rikli. 



While the mere question of priority is a very unimportant one in scientific 

 research, it must be admitted that Haberlandt was the first to discover this par- 

 ticular sheath in the Cyperacece. 



