EXPEKIMEls^T STATION EEPORT. 347 



On September 15th an sittempt was made to graft the tip, basal 

 Iwaneh, and the piece which was cnt on Septeml^er 5th and left 

 attached to S. B. 3, to shoots of the Main Branch between pots A 

 and B, one graft of the basal end of S. B. 3 upon the basal end cf 

 one cf the shoots, and two of the apical ends of S. B. 3 and its 

 basal branch upon the apical ends of other shoots. In all oases the 

 current would be re^'ersed in that portion of the gi'aft in which it 

 was already reversed before the graft. As was to be- expected, all 

 of the grafts failed. 



The }X>rtion of S. B. 3 extending backwards over pot ^ to the 

 point of separation of September 5th has kept green until now 

 (October 25th), but the leaf farthest away from the pot became 

 yellow and dropped on October 7th, while the small branch spring- 

 ing from this leaf is turning yellowish also. 



The Roots. — On August 25th, when the soil was perfectly dry, 

 some of the roots in the box were carefully laid bare and examined. 

 They consisted of potatoes up to nine inches in length and about 

 one inch in diameter. All large roots and all small rootlets were 

 perfectly turgid, and no dried up roots were found. Dry raphia 

 bands were tied around several of the larger roots, and these were 

 then covered up again with perfectly dry soil. On September 

 20th and October 4th they were again examined and were found to 

 be decreasing in circumference, as the raphia bands were very 

 loose upon them. On October 12th they were found of the same 

 size as on October 4th, , and additional bands were put on, labeled 

 with tags so as to distinguish them from the old ones. On October 

 20tli the bands of August 25th were found to be tight and im- 

 movable on the roots, while those of October 12th were lying in 

 shallow indentations, but had not cut into the skin. 



The dying of the leaves and branches between pots 3 and 4 

 ]3ointed to an insufficient supply of water, which might arise 

 through diseased roots in pot 3, which was Avell watered. On 

 October 20th, some of the roots of pot 3 were laid bare. JSTone of 

 them had enlarged into potatoes, but all were found to be appar- 

 ently healthy and vigorous. 



Discussion. — Through numerous experiments of Strasburger 

 (Leitungsbahnen) and others before him, it has long been known 

 that a reversal of the water current in plants is possible, without ap- 

 parent detriment to any part. Two trees which had branches grown 



