1\ Holm — Studies in the Cyperacece. 17 



plants, counting the cotyledon as the first, the epiblaste as the 

 second and the sheathing leaf as the third leaf of the young 

 plant. We might be allowed to suggest that the epiblaste has 

 become undeveloped in the Cyperacece, but without influencing 

 or rather without disturbing the normal arrangement of the 

 leaves, as we find them in Fuirena and all the others exam- 

 ined. It was the frequent development of a stem-part between 

 the cotyledon and the sheathing leaf, which led Warming to 

 adopt the explanation of these three organs, including the 

 epiblaste, as independent ; but, strange to say, Warming does 

 not in his paper upon this subject (1. c.) enter into any discus- 

 sion as to the severe objections raised, by Yan Tieghem against 

 this theory. Yan Tieghem denounces the epiblaste as a leaf, 

 because it does not receive any mestome-bundles from the axis ; 

 the sheathing leaf will, therefore, necessarily be situated above 

 and " at the same side " as the scutellum, and can consequently 

 not be independent of this. He, finally, demonstrates that the 

 supposed internode (j) is only a node according to its anatom- 

 ical structure, but a node, which has become unusually 

 stretched, so that the cotyledon and the sheath have become 

 somewhat separated from each other. These very serious objec- 

 tions are, of course, a heavy blow to the theory regarding the 

 existence of three independent leaves, an explanation which 

 otherwise seems so very natural and in good conformity with 

 the rules of morphology. We venture, however, to suggest 

 that the epiblaste may be a leaf-primordium and that it stays 

 as such with no mestome-bundles developed, and as a leaf, 

 which is often suppressed entirely. We will, also, state that 

 we cannot find any decided objection in considering the cotyle- 

 don as a leaf, independent of the epiblaste and of the sheath- 

 ing leaf, even if, as Yan Tieghem has proved, the stem-part is 

 only a node. There is among the numerous and most import- 

 ant agrostologic papers by Duval-Jouve one (1. c.) in which he 

 describes the nodes of Eleusine, Cynodon and other Graminece 

 as bearing more than " one leaf," from one to two or even 

 three ! This same fact is very familiar to us, when we remem- 

 ber the peculiar, dense-leaved nodes of Diplachne, Munroa, 

 Buchloe and several other North-American grasses. We 

 might also state, that it is not quite certain that the epiblaste 

 is constantly present only as a rudimentary organ, since 

 Didrichsen (1. c.) has figured this organ taken from Avena 

 sativa, where it shows a distinct nervation, corresponding to a 

 very finely lobed margin. We believe, however, that a con- 

 tinued research will throw a clearer light upon this subject, 

 and there is no doubt that seedlings of our native grasses and 

 sedges will show some facts that may be helpful for the expla- 

 nation of this remarkable manner of germinating. We will, 



Am. Jour. Scl— Fourth Series, Vol. IT, No. 1.— Jul?, 1897. 

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