1908] Observations ox Seedling Plants. 171 



several pairs of secondary roots (Figs. 13, 14 and 17); the so- 

 called "scutellum" (S), which is more or less shield-shaped, and 

 closely appressed to the endosperm, which it absorbs; further- 

 more, the sinall lobe-like organ called "epiblast " (E)), which is 

 situated opposite the scutellum, and which is not developed in 

 Zea; between the scutellum and epiblast is the plumule (PL.) 

 covered by a sheath, the so-called "coleoptile," which in Zea 

 is borne on a stem-like organ of quite considerable length. The 

 first green leaf of the seedling (L.) is to be seen in Fig. 17, having 

 broken through the coleoptile. Considering the position of 

 these three organs, scutellum stands opposite the epibla.st, and 

 the coleoptile is not onlv situated on the same side of the axis as 

 the scutellum, but, furthermore, it turns like this toward the 

 plumule, or let us say toward the first green leaf. In other 

 words, in cases where the epiblast is suppressed, which is very 

 commonly the case, the scutellum and coleoptile appear as two 

 organs situated above each other, on the same side of the axis. 

 The question then arises to define whether the cotyledon is 

 represented by one or several of these organs, and whether these 

 organs are really leaves, parts of leaves or independent leaves. 



Strange to say, but according to Richard, A. de Jussieu, 

 Hofmeister, and Sachs, the coleoptile should represent the 

 cotyledon, while the scutellum and epiblast should merely be 

 parts of stem and root. Another view was held by Schleiden, 

 and Decaisne, who identified the scutellum and the epiblast 

 as the cotyledon, the coleoptile as the first leaf succeeding 

 this. Or these three organs may be defined as cons- 

 tituting the cotyledon, as proposed by Gaertner, who has 

 been followed by Hegelmaier, Klebs, Van Tieghem (1872), 

 Celakovsky and Schlickum; thus the scutellum should represent 

 the absorbing portion of the cotyledon, the coleoptile its sheath, 

 while the epiblast should be a mere protuberance of the coleorhiza 

 (Schlickum) or a part of scutellum (Van Tieghem , Celakovsky) ; 

 to this may be added that Van Tieghem, by means of the 

 anatomical method, reached the conclusion that the stem-like 

 portion between the coleoptile and scutellum is not an internode, 

 but a node which has become unusually stretched. 



Depending more on the mutual position of these organs than 

 on their structure and homologies Warming has made a very 

 different suggestion, and he considers scutellum alone as the 

 cotyledon, the epiblast as the first leaf succeeding this, and the 

 coleoptile as the second, thus presuming that the epil)last should 

 actually have become completely suppressed in the Cyperncece; 

 hence the peculiar position of the sheath just above the cotyledon 

 in these. According to this .same* author the stem-like portion 

 necessarily becomes an internode. The reason why Van Tieghem 



