Friesia IV, 1-2

-75 -
(1888), Urophiala mycophila Vuillemin (1918), Zygosporium mycophilum
(Vuill.) Sacc. (1911) , Urophiala parasitica (Grove) A. L.
Smith (1920) and Pimina my cophila (Vuill.) A. L. Smith (1920).
D e s c r i p t i o n . The falces (M a s o n has suggested t he term
of falx for a conidiophore of Zygospor i um ) are borne laterally and
singly on the hyphae. They are ere ct, consisting of 4 cells, her e
mentioned after position in distal succession: 1 ) a hyaline, cylindrical
, basa l cell, ab . 2-3 I-' in length, 3 I-' in breadth; 2) a smoked
cylindrica l cell 7.5- 13.51-' (11.21-' )1) in len gt h, ab. 3ft in bread t h ;
3) a dar ker smoked prophialide, dorsiventral, 12.8- 15.81-' (14.51-')
in len gth, 6-7.5 1-' (7 .11-') in breadth. The dor sal pr ofile of t he pro ­
phialide is sligthly s-formed, its ventral side is equip ped wit h 3
short st umpy beakst ; the en d of whi ch is about 1.51-' in br e.adth.
They are loc ated on the same t r ansve rse axi s, which is situated
ab. 3I-' from the apical wall of t he cell o The two out er beaks are
located symmetrically to the middle one, at angles of ab. 45-60°.
The phialides are borne on t he beaks, and t hey are hyaline, obpyriform,
curving upwards, 4.5-5.31-' (4.71-') in length, 3-3.8ft (304ft)
in breadth. The conidia are hyaline, ellipsoid, 7.5-8.3 X 4.5-5.31-'
(7 .8 X 4.81-') . Finally , 4) the 4th cell in the succession is the so ­
called apical filam ent. This is mid-placed, hyaline to faintly smoked ,
cylindrical, 7.5-121-' (9.21-') in length, 2.3-3ft (204ft) in breadth,
the apical wall of which bursts at the time of maturing of the
conidiophore, leaving a circular aperture with remnants of the
apical wall left like a collar.
As pointed out by V u i Il e m i n (1910) , sometimes a secondary
conidiophore is formed (see Fig. li), the secondary falx consisting
of only the prophialide and the apical filament. They occur rather
infrequently, only 11 of 1000 falces had a secondary falx developed,
i. e. in ab. 1 % of the cases.
Previous records on the morphology of Z. parasiticum seem to
have been based only on two findings : the original collection of
Pintina parasitica Grove, critically studied by M a s o n (l. c.), and
V u i Il e m i n's (l. c.) material of Urophiala mycophila. A comparison
of measurements is made in Table 2. S a c c a r d o (1911)
who found the fungus on Botrytis does not give any measurements
in his description.
1) Measurements in parenthesis are averages of 10 measurings.
2) M a s o n (1. c.) regards all three «st um ps» as one beak. leannot see
the reason fo r this eoneeption.