T. Holm — Studies in the Cyjjeracece. 307 



of the tissues of the rhachis proper. When we compare 

 the structure of this organ and of the rhachis with that of a 

 rudimentary bract and the base of the panicle to which it is 

 adnate and with which it forms one solid body, we then per- 

 ceive exactly the same conditions in respect to the tissues of the 

 bract being well separable from those of the culm, even if they 

 are united into one body, but of two distinct structures. In 

 other words, the internal structure of the cushion-like body 

 resembles that of a clado-prophyllon in Cyjoerus with its large 

 collenchymatic tissue to such an extent, that as far as concerns 

 the structure alone the organs appear to be identical. 



Furthermore when we remember that the fore-leaves of 

 Graminece are open, the position of this little body in the in- 

 florescence may be Avell comparable with one of these, since it 

 only covers one, the upper, face of the respective branch. 

 Finally, as we have already stated, the function is, also, the same. 

 We, therefore, believe that the small bodies, always observable 

 at the base of the secondary branches of inflorescences in 

 Graminece, most distinct in large panicles, that these represent 

 rudimentary prophylla, identical with those described above as 

 characteristic of Cyperacece. 



It would be highly desirable if American agrostologists 

 would reexamine these organs in our Graminece, for it may be 

 that some genera or species exist in which they are developed 

 somewhat further and more distinctly as foliar organs. But in 

 regard to our own investigations, we can only say that as far as 

 concerns " position, function and structure " these organs may 

 be regarded as rudimentary leaves or "fore-leaves" in this 

 particular case. 



Brookland. D. C, July, 1904. 



