44 DR. A. D. WALLER ON THE 
out by MacDonald and Sowton in the case of the current of 
injury of mammalian nerve. Clearly, however, the explanation 
invoked by these authors for their case—viz., augmentation of 
concentration-current by cooling—will not apply to the present 
case. I have no very dogmatic explanation to offer; it looks to 
me very like an imbibition current at a eut surface. 
§ 24. A blaze-current provoked in a vegetable organ during its 
manifestation of a current of injury is, in general, opposite 
to it in direction, whatever may have been the direction of the 
exciting current. Du Bois Reymond would probably have called 
it a negative variation of a previous current. 
Blaze-currents caused by excitations of moderate strength at 
sufficiently long intervals in the course of a declining injury- 
current are of diminishing magnitude. The smaller the injury- 
current, the smaller is its negative variation. 
Fig. 7.—PA (Pisum sativum), Negative variations of Current of Injury. 
Volt 
0-05 
Q:O4— 
0-034 
one 
O:01- 
6-01 = 
/\ 
L | 1 L | L L 
] f 
ihour D TI 
§ 25. Fourra Day.—We intend to find out to-day what sort 
of magnitudes the currents of different peas present: whether 
they differ at different stages of maturity, whether individual peas 
of the same pod vary more or less than peas of different pods, 
and so forth. 
$26. I begin with a comparison between two very different 
pods: one quite ripe and fully distended, of which the cooked 
