676 REPORT—1 896. 
Schwendener objects that although a continuous column of water 
cannot be raised by air pressure to a greater height than that of the 
barometric column, yet when broken into a number of columns, as in the 
case of a Jamin chain, that a column considerably over 10 m., even as 
much as 13 or 14 m., of water can be suspended. This, though not fatal 
to Strasburger’s conclusions, is no doubt a serious criticism. For if 13 m. 
can be supported, some of Strasburger’s experiments are inconclusive. He 
finds that a branch can suck up a poisonous fluid to over 10 m., and, as 
above explained, argues that all ascent above that height, not being due 
to barometric pressure or to the living elements (since the wood is 
poisoned), is for the present inexplicable. But, if Schwendener is right, 
the effect above 10 m. may have been due to atmospheric pressure. 
Askenasy (loc. cit. infra, 1895, p. 6) objects to Schwendener that the 
supposed action cannot be continuous. By repeating the diminution of 
air pressure at the upper end the movement of water becomes less and 
less, and sinks to almost nothing. Askenasy adds, moreover, that the 
amount of water which could be raised according to Schwendener’s theory 
would be very small. 
One diticulty about Schwendener’s theory is that the result depends 
on the length of the elements of which the chain is made up (such 
element being a water column plus an air bubble). In his paper ‘ Ueber 
das Saftsteigen’! he finds that the elements of the chain in /agus equal 
in round numbers 0°5 mm. In his paper? ‘ Wasserbewegung in der 
Jamin’schen Kette’ he finds the element in Acer psewdo-platanus=0'9 mm., 
in Acer platanoides and Ulmus effusa=0°2. But the calculation (1892, 
p. 934) is based on the existence of a chain in which the water columns 
are each 10 mm. in length ; a condition of things which he allows does not 
occur in living trees. 
But even if we allow Schwendener to prove theoretically the possi- 
bility of a Jamin chain being raised to a height much greater than that 
of a barometric column, I do not think he invalidates Strasburger’s posi- 
tion. Schwendener’s idea necessitates the travelling of a Jamin chain as 
a whole, 7.e., the translation, not only of water, but of air bubbles. But 
this cannot (as Strasburger points out) apply to his experiments on coni- 
fers, in which the movement of air to such an extent is impossible.* 
And for the case of dicotyledonous woods, Strasburger has shown that 
the movement of air is excluded by the fact that transverse walls occur 
in the vessels at comparatively short distances. In Aristolochia the sec- 
tions may be as long as 3m., but in ordinary woods, according to Adler,‘ 
we get: Alnus, 6 cm.; Corylus, 11 cm.; Betula, 12 cm. ; Quercus, 
57 em. ; Robinia, 69 cm. These facts seem impossible to reconcile with 
Schwendener’s views. 
Action of the Poisonous Fluids in Strasburger’s Huperiments.— 
The question whether the living elements are killed in Strasburger’s 
experiments is of primary importance in the problem. 
Schwendener does not criticise it at length ; he seems to assume °—as 
far as I can understand—that since the death of the tissues extends 
gradually from the cut end upwards, there are living cells in the upper 
' K. Preuss. Ahad. 1886, p. 561. 
2 K. Preuss. Ahad. Sitz., 1893, p. 842. 
3 ‘Ueber das Saftsteigen,’ Hist. Beitrdge, v. 1893, p. 50. 
' As quoted by Strasburger. 
5 Zur Kritik, loc. cit., 1892, p. 935 
