440 MR. G. MASSEE ON THE 
Tubercularia, Tode, another genus included in the Hypho- 
mycetes, is morphologically indistinguishable in all essential 
features from Stilbum, but separated by systematists on account 
of the shorter stem, the subglobose head being nearly, or in many 
species quite, sessile on the matrix, as in the well-known Tuber- 
cularia vulgaris, Tode, which forms coral-red pustules on 
decaying or dead branches. 
Tubercularia includes about seventy species, several of which 
are the conidial condition of ascigerous fungi belonging to the 
genus Nectria. 
About thirty members of the long-stemmed or Stilbum-forms 
are also known to represent the conidial condition of species of 
Nectria or Spherostilbe, the name given by Tulasne to those 
species of the old genus Nectria having l-septate spores and a 
Stilbum as the conidial form of reproduction (5). 
In many instanees the genetic relation between a conidial 
condition and its higher form of fruit is not distinctly proved ; 
the researches of Tulasne (6), Hartig (7), and others, however, 
leave no doubt as to the relationship between Stilbum or 
Tubercularia and species of Nectria. 
The general structure is alike in all known instances. A 
compact parenchymatous base or stroma forms in the substance 
of the matris, and eventually projects above its surface as a 
cushion-like body; from the superficial cells of this stroma the 
fertile hypha—conidiophores or basidia—of the Tubereularia or 
Stilbum originate. Ata later date the primordia of the ascigerous 
or Nectria-torm of reproduction appear in the peripheral portion 
of the stroma ; these gradually develop into the characteristic red 
perithecia which stud the surface of the stroma in Nectria 
proper, the conidial phase being obliterated by the later develop- 
ment of the perithecia; whereas in Spherostilbe the long- 
stemmed  S£lbum-condition and the ascigerous perithecia are 
both present at the same time (Pl. 15. fig. 7). 
A second,and even third conidial form of reproduction, also 
produced by the stroma, is present in some species of Nectria, 
but appear to have no bearing on the subject under con- 
sideration. 
In addition to those form-species of Tubercularia and Stilbum 
known for certainty to represent the conidial condition of species 
of Nectria or Spherostilbe, many species belonging to each of these 
genera exist that have not up to the present been correlated 
