132 Salmon.— Further Cultural Experiments with 
‘cut’ places, and on one leaf penetration from the appressorium, and the 
formation of a haustorium in an epidermal cell opposite the ‘cut’ had taken 
place. By the next day the haustorium had developed lobed processes. 
On the seventh day young conidiophores were produced, on little patches of 
mycelium, opposite the ‘ cut ’ on two leaves, and on the tenth day mature 
conidiophores with ripe conidia. On the fourteenth day the leaves were 
translucent, and hundreds of ascospores were visible which had been sown 
over the surface of the leaf exposed to the bursting perithecia. The 
ascospores had germinated, and produced appressoria, but, except at the 
‘ cut ’ place of two leaves (as noted above), had been unable to cause 
infection. In two cases, however, at a distance of 2 mm. beyond the region 
opposite the ‘ cut,’ an ascospore had germinated, and produced a lobed 
haustorium, and a few short, thick hyphal branches from the appressorium. 
/3, Injury by pin-pricks. 
In the first experiment (No. 6) twelve pricks were made in a barley leaf 
with a pin (causing holes 0-5-0*75 mm. in diameter), at a distance of 3 mm. 
from each other, in two parallel lines across the width of the leaf. Conidia 
were sown round all the holes, and in the region between the two lines of 
holes. On the seventh day minute flecks of mycelium proceeding from 
germinating conidia were visible at the edge of two of the holes. On the 
ninth day a few conidiophores appeared round these two holes. On 
the fourteenth day a few conidiophores were still present round one of the 
holes. The leaf was now nearly dead, and translucent at the inoculated 
places. No production of conidiophores took place in the region between 
the lines of pin-pricks, but two conidia, each at a distance of 0-75 mm. from 
the nearest hole, germinated and produced a small patch of barren mycelial 
hyphae. 
In other experiments (Nos. 6, 10) nine pricks were made with a needle, 
at a distance of 3 mm. from each other, in a single row on a barley leaf. 
No infection followed the inoculation of this leaf. The same negative result 
was obtained when a circle, 4 mm. across, of seven pin-pricks was made on 
a barley leaf, and conidia sown on the cells in the centre of the circle. 
Ascospores were then sown on barley leaves, in which nine to fourteen 
pin-pricks, in a longitudinal row, at a distance of 2 mm. from each other, 
had been made. No infection resulted ; the ascospores germinated 
vigorously, and produced appressoria, but were not able to form any 
mycelial hyphae. 
y. Injury by cork-borer. 
In one experiment (No. 6) a circular hole, 4 mm. in diameter, was 
stamped out of a barley leaf with a cork-borer. Conidia were sown, on 
December 5, and on the fourth day clear signs of infection were visible on 
