54 
FETCH : 
of a mycelium under various conditions. By placing the 
mycelium in an Esmarch dish with a little water, it may be 
determined that growth only occurs if the mycelium is 
attached to dead tissues ; if a piece of the tangle which 
contains dead leaves and twigs is used growth may be 
recorded, but if the piece of mycelium is attached to living 
leaves only no growth takes place. Attempts have been made 
to extend this rough observation, but so far without much 
success. It was found that in the Esmarch dish growth 
occurred during the first night, and then practically ceased ; 
one series of observations may be quoted : — February 23, 
4 P.M., to February 24, 10 a.m., 10*8 mm.; February 24, 10 a.m. 
to 6 P.M., 0 • 9 mm.; February 24, 6 p.m., to February 25, 8 a.m., 
no growth. The following apparatus was then set up: — A 
horizontal chamber was formed by cementing a sheet of glass 
to either side of an oval gun metal frame ; the mycelium 
attached to dead twigs, &c., was laid in this, in a thin film of 
Avater on the lower glass. Two thermometers, a wet and a dry 
bulb, were inserted through openings in the frame, and a 
current of moist air was drawn slowly through the apparatus. 
With this arrangement the humidity within the chamber was 
constant. Measurements were made by observing the position 
of the end of the strand by means of a travelling microscope. 
The observations may be summarized as follows : — 
Mycelium gathered 3 p.m. ; experiment begun 4 p.m., 
October 10. 
4 P.M. to 5 P.M., Oct. 10, no growth. 
5 P.M., Oct. 10, to 8 A.M., Oct. 11, 3 ”45 mm. 
8 A.M., Oct. 11, to 6 P.M., Oct. 11, 0*75 mm. 
6 P.M., Oct. 11, to 6 A.M., Oct. 12, 0”6 mm. 
6 A.M., Oct. 12, to Oct. 19, no growth. 
It is probable that the metal frame may have injuriously 
affected the mycelium, though the inner side of the frame was 
waxed in order to avoid that. As no other apparatus was 
available at the time, the experiment was not carried further, 
and it has not since been found possible to resume it. But 
it would seem probable that growth occurs in bursts, and that 
these are of such short duration that they do not afford much 
scope for experiment. 
