On the Germination and the Polyembryony 

 of Poa pratensis, L. 



(Preliminary note) 



By 

 Makoto Nishimura. 



With Plate I 



I. Germination. — A study of the comparative morphology and 

 development of Poa pratensis, Phlettm pratense and Setalia italica 

 has been undertaken by the writer. The observations were completed 

 in 1919 at Columbia university, New York City. This preliminary 

 report is limited to two chapters, namely, " Characteristic Features 

 Associated with Germination" and the " Polyembryony in Poa 

 pratensis." 



The grains used in the study of these plants were grown in 

 Zurich germinators. The principal points of interest relate to the 

 viability of the grains, the character and nature of the coleorhiza 

 and epiblast, and finally, to the occasional development of poly- 

 embryony in the case of Poa. pratensis. 



One of the interesting features associated with the germination 

 of the grains was the rather common development of absorbing hairs 

 on the coleorhiza (Fig. 1). Though it is obvious that they are of prime 

 importance in establishing the seedling in the soil, no reference has 

 been found which bears on the nature and development of these hairs. 

 They appear practically with the first emergence of the coleorhiza. 



These outgrowths correspond in origin and structure to ordinary 

 root hairs, and the nucleus shows the same range of variation with 

 respect to its relation to the epidermal cell as the case of the root 

 hairs, reported by Haberlandt 15 (1887), Roberts 27 (1916) and others. 

 The hairs are usually developed near the tip of the coleorhiza ; but 

 in some cases the tip cells form the hairs, as do also the upper cells 

 of the coleorhiza, which develop into long active hairs. This appears 

 to be a distinctive feature of the coleorhiza as contrasted with the 

 roots where the root hairs are usually found a short distance from 



