

68 BOTANICAL GAZETTE. [ March, 



while hydrochloric acid dissolves the raphides without effer- 

 vescence, proving them to be calcium oxalate. The fibres 

 are proven to be lignified from their reactions with phloro- 

 glucin and hydrochloric acid, also with aniline sulphate and 

 sulphuric acid. Treated with iodine and sulphuric acid a 

 reddish-yellow color is produced, which confirms the above 

 statement. Knowing that these fibres are hard-walled, lig- 

 nified cells, and that they appear scattered through the par- 

 enchyma, they may therefore be placed among the scleren- 

 chymatous tissues. Similar cells to the above, occurring 

 in Aroideas. Rhizoohoracefe. Nvmnh»>ar.pfp. and psnpri;tllv 



thqse 



Monsteri 



sur- 



" internal hairs" by de Bary. Concerning them he says: 1 

 " Numerous hairs are contained in the cavities and passages 

 of the lamellar parenchyma. * * * * They closely re- 

 semble sclerenchymatous fibres and were therefore first de- 

 scribed as ' bast cells ' by Schleiden." Farther on he makes 

 the statement that hard- walled hairs are fundamentallv re- 

 lated to sclerenchymatous fibres in every respect and are 



special cases of the latter, distinguished by form and distri- 

 bution. 



On taking longitudinal sections from various parts of the 

 plant, the fibres are found to occur in every part. But in no 

 part are they found in so great numbers nor so perfectly de- 

 veloped as in the exocarp or outer portion of the fruit. Here 

 they resemble true bast fibres, with but little branching, while 

 in the leaf lamina and spathe, especially, they are very slen- 

 der and variously branched, filling the interstices of the 



rounding tissue and resembling the "internal hairs" de- 

 scribed by de Bary. 



For a general description of the fibres it may be stated 

 that the walls are very evenly thickened, possessing no pro- 

 jections nor characteristic markings. They are firm in text- 

 ure but not brittle as wood fibres. In length they are from 

 .9 mm. to 1.6 mm. ; in diameter from .015 mm. to .03 mm. 

 Their contents are similar to those of the surrounding cells, 

 but slightly granular. They occur in the parenchymatous 

 tissue situated in the interstitial or intercellular spaces. 



While the fibres differ much in size and assume a variety 

 of shapes, due mainly to their promiscuous branching, we 

 find the raphides to be of nearly uniform size and form. 

 Like the fibres they occur throughout the plant in the par- 

 en chymatous tissue, but most abundantly in the fruit. Here 



'Comp. Anat. of Phanerogams and Ferns. 



