122 Biffen . — On the Biology of 
parts. At the same time a bright orange red pigment, the 
4 bulgarine 5 of Zopf, was formed within the hyphae. In 
the case of strongly-growing spores the swelling continued 
until the diameter of the hypha was increased three or 
four-fold. Except that a number of fusions occurred in 
hyphae extending beyond the hanging-drops, possibly as an 
aid for the transference of plastic substances, nothing further 
was to be noted in these cultures. This result does not 
agree with those of Brefeld and Tulasne, who have stated 
that the spores on germination put out either a rudimentary 
or a well-developed mycelium from which numbers of rod- 
shaped conidia were abstricted \ Further experiments with 
various media showed, however, that either result could be 
produced at will. Thus on sowing the spores in distilled 
water the colourless ones germinated in about twenty-four 
hours and gave rise to a mycelium about the length of the 
original spore, from which numbers of conidia were abstricted, 
while the coloured spores behaved in a similar fashion after 
two or three days. In a watery extract of oak-wood, or in 
a gelatine made up with a watery extract of cow-dung, both 
colourless and coloured spores gave rise to a long, branching 
mycelium bearing clusters of conidia. It would appear 
therefore that the formation of the conidia is determined 
by the supply of available nutriment ; where there is little, 
conidia are produced at once, while where there is plenty, 
mycelium only is formed. 
The conidia themselves swelled considerably on germination 
and gave rise directly to a mycelium, which on transference 
to a moist, sterile block of oak-wood developed rapidly and 
infected it 2 . 
The germinating ascospores also are capable of infecting 
oak-wood directly, for on removing them from beer-wort 
gelatine to sterilized blocks they soon gave rise to a thick 
mycelium. As I never succeeded in finding conidia on the 
1 Vide Brefeld, Heft x, Ascomyceten, ii, Plate XI, for figures. 
2 For details of method, vide Marshall Ward, Phil. Trans., voh clxxxix, p. 123, 
1897. 
