178 FUNGI. 
threads of Tilletia,* and similar acts of conjugation, as observed 
in some species of Ustilago. Whether this interpretation should 
be placed on those phenomena in the present condition of our 
knowledge is perhaps an open question. 
Finally, the spermogonia must be regarded as in some occult 
manner, which as yet has baffled detection, influencing the per- 
fection of sporidia+ In Zhy- 
tisma, found on the leaves of 
maple and willow, black pitchy 
spots at first appear, which 
contain within them a golden 
pulp, in which very slender 
corpuscles are mixed with an 
abundant mucilage. These 
corpuscles are the spermatia, 
which in 2hytisma acerinum 
are linear and short, in Athy 
tisma salicinum globose. When 
the spermatia are expelled, the 
i x Re stroma thickens for the pro- 
a ba - _ duction of asci and sporidia, 
ae 101.—Tilletia caries with conjugating which are afterwards developed 
during the autumn and winter. 
Several of the species of Hysteriwm also possess spermogonia, 
notably H. Fraxini, which may be distinguished from the asci- 
gerous perithecia with which they are associated by their smaller 
size and flask-like shape. From these the spermatia are expelled 
long before the maturity of the spores. In Hypoderma virgul- 
torum, H. commune, and H. scirpinum, the spermogonia are 
small depressed black capsules, which contain an abundance of 
minute spermatia. These were formerly regarded as distinct 
species, under the name of Leptostroma. In Stictis ocellata a 
great number of the tybercles do not pass into the perfect state 
* Berkeley, in ‘Journ. Hort. Soc.” vol. ii. p. 107; Tulasne, ‘Ann. d. Sc. 
Nat.” (4™¢ sér.), vol. ii. tab. 12. 
+ Tulasne, ‘‘New Researches on the Reproductive Apparatys pf Fungi ;” 
‘* Comptes Rendus,” vol. xxxv. (1852), p. 84]. : 
