luckan: abutilon theophrasti. 221 



line sulphate, and very little, if any, with Sudan III. In one test 

 with the chloroiodide of zinc the inner portion of the cell wall of 

 the basal region stained purple, indicating cellulose in the position 

 shown in fig. 5. Some of these hairs showed nuclei situated in the 

 basal part, but very little cytoplasm could be demonstrated. 



Haberlandt, in his discussion of multicellular absorbing hairs, 

 makes the statement: "If such a hairy covering is easily wetted 

 and rapidly absorbs drops of water; if, further, the hairy leaf 

 rapidly recovers its turgidity when immersed or besprinkled in 

 the withered condition; if, finally, places for the entrance of water 

 through the hairs are indicated by the presence of thin-walled 

 basal cells with abundant protoplasmic contents, it may be safely 

 assumed that the hairs in question serve to some extent for the 

 absorption of water." The imperfect cutinization of the walls, 

 above noted, would allow the water to pass to the inside of the 

 hair. The structure of the stellate hairs, together with their oc- 

 currence only on the veins, and the amount of water absorbed by 

 wilted leaves, as mentioned, lead me to believe that these hairs 

 are water-absorbing hairs. 



The other form of clothing hair is like a single ray of the stellate 

 type; here the pits in the basal portion show up plainly (fig. 7). 



The glandular hairs are of two kinds; one is long, being made 

 up of from twelve to fifteen cells, while the other is only four to 

 five cells in length. The basal cell of the long hair is enlarged 

 (figs. 3 and 4). The cell just above it has its side walls cutinized 

 throughout, so that it shows up as a bright-colored ring when 

 stained with Sudan III or chloroiodide of zinc. The remaining 

 cells of the hair are pro\aded with a veiy thin cuticle. The apex 

 is rounded out, and here drops of oil collect as it is secreted. The 

 short glandular hair has its cells little differentiated, but the basal 

 cell is slightly larger than the neighboring cells (fig. 8). These 

 smaller hairs occur along the midrib and the larger veins, and 

 Nestler ( '99) says in some of the species of Abutilon they function 

 as hydathodes, or hairs which excrete water. The hairs are ad- 

 vantageously situated for this, and as they contain living pro- 

 toplasts they could possibly function in this way. 



The stomata are not specialized, and are found in gi'eater num- 

 bers on the lower epidermis, where they average 300 per square 

 millimeter as compared with 250 on the upper surface. 



The radial and outer walls of the epidermis are not especially 

 thickened, but the inner wall of some of the epidermal cells be- 

 comes much thickened and mucilaginous and protrudes down into 



