1896.] Water Current in Cucmii her Plants. 455 



tii icily visible in the veins of every leaf in 15 minutes but for 

 the gelatine plugs, as we have seen from the preceding experi- 

 ments. March 23, 11:00 a. m. Two-thirds of all the foliage 

 of this vine is now dry-shriveled, and the remainder is very 

 flabby, but there is not a trace of eosine visible in any of the 

 leaves, not even in those which are near the cut end and still 

 living. Sun shining, hot, some wind outside. Tempera- 

 ture in the shade, 6 inches above the bench, 27° C. ; in sun, 

 30° C. ; dry bulb, 26.5° C. ; wet bulb, 22° C. Active transpir- 

 ation. 1:45 p. m. Nine-tenths of the foliage is crisp-dry. 

 No trace of color in any part of the stem or foliage. The stem 

 was now removed from the fluid and cut for examination with 

 the following results : One-half centimeter up. — Most of the 

 pitted vessels were full of the black gelatine, one showed a rim 

 of gelatine with a central air bubble. Spirals mostly not full. 

 Diffuse stain in the parenchyma. The stain has passed 

 through the gelatine itself in many instances (owing perhaps 

 to its liquefaction on a. m. of March 23, when a beaker of 

 water, in wdiich the eosine bottle rested, became lukewarm and 

 a beaker of gelatine on the bench near by became fluid). Six 

 cm. up. — Comparatively few pitted vessels have gelatine in 

 them ; some of these are full, others have only a rim of gela- 

 tine around a succession of air bubbles. Eight cm. up. — The 

 torn central stem cavity, which is still visible, contains no 

 gelatine. A few pitted vessels contain gelatine mostly as rims 

 around the walls, air being in the center. Ten cm. up. — No 

 gelatine. Stain very feeble, diffused somewhat into the par- 

 enchyma. About £ of the pitted vessels unstained ; color re- 

 stricted to the spiral vessels in one bundle. Twenty cm. up. — 

 No gelatine. Stain slight, not entirely restricted to the bun- 

 dles but diffused out into the parenchyma on one side of the 

 stem. Forty-three cm. up. — Slight traces of stain in 7 bun- 

 dles, restricted to the spirals in 4 ; in two other bundles, only 

 the outer angle of the xylem wedge is stained, on one side 

 or the other, i. e., those vessels which frequently fill with bac- 

 teria in advance of the rest of the pitted vessels, when the 

 plant suffers from cucumber wilt. Seventy-five cm. up. — Stain 

 restricted to six bundles, and very slight; confined to the 



