Between Droscra filiforinis and D. intermedia. 91 



three and show noteworthy differences. Those of D. Jilifonnis 

 are 38 // long by 24 jx wide, and one guard cell is usually 

 larger than, or somewhat obliquely placed to, the other, while 

 a more or less evident sinus exists at their opposed ends 

 (Plate XII, Fig. 6a). The chloroplasts of the guard cells are 

 20-22 in number, and measure 3.2 p. across. In the hybrid 

 the stomata are on the average 3 2 /i X 25 ji, and show a very 

 slight tendency toward inequality of size or position. (Fig. 

 6(5). The chloroplasts are 15-17 in number and measure 2.5 

 p. across. In D. intermedia the stomata measure 26 /i X 25 /i ; 

 the guard cells are very neatly crescentic and fitted at their 

 ends (Fig. 6f). The chloroplasts are 12-14 '" number and 

 measure 1.8 // across. 



The blade of the leaf is tentacular throughout on its upper sur- 

 face. The general color of the lamina of the three forms is mark- 

 edly different. Leaves of D. filiformis might be described as 

 pinkish-green, those of D. intermedia as deep crimson green, 

 while those of the hybrid are averagely intermediate to the 

 naked eye. Microscopically examined, these differences are 

 found to be due to the relative distribution of a rich crimson- 

 red pigment, which is only present in the tentacular hairs. In 

 D. filiformis it is wholly confined to the oval or elliptic head 

 of each hair, there being a sharp contrast in color between the 

 green top of the hair-stalk and the red base of the head. In 

 D. intermedia the pigment is richest in the head, but is dis- 

 tributed in the cells of each hair throughout two-thirds of its 

 length. In the hybrid the pigment is less rich than in the 

 last, and extends throughout one-third to rarely one-half the 

 length of the stalk. 



The tentacular hairs of all three vary greatly in length, so 

 that no exact comparison is possible. The club-shaped head 

 of each in D. filiformis is broadly elliptic and is on the average 

 220 X 165 //. The head of each hair in D. intermedia is ovate- 

 truncate and mea.=ures 230 X 105 //. That of the hybrid is 

 elliptic-ovate in outline and measures 210 X 125 )i. 



/ 



