286 INTRODUCTION TO THE STUDY OF FUNGI 



through the bark at regular distances, scarcely a quarter of an 

 inch apart. Towards one end of the twig the prominences 

 will doubtless appear of a darker colour, almost 

 blood-red, and, intermediate . between the two, 

 pink pustules sprinkled with red dots. The dark 

 red pustules are composed of a number of minute 

 red bodies clustered together, the perfected condition 

 of the parasite (Fig. 133). By removing the bark 

 it will be seen that the pink bodies have a paler 

 stem, which expands above into a rather globose 

 head, covered with a mealy bloom. This is the 

 Tubercularia, which at its base penetrates to the 

 inner bark, and there the threads of mycelium 

 branch in all directions, within the bark, but do 

 not extend to the woody tissues beneath. The 

 head, more closely examined, will be found to 

 consist of delicate parallel threads, which are 

 compacted together into a common stem, with its 

 Twig with head. Some threads are simple, others branched, 

 Tubercularia, ^ea^g here and there little bodies, easily detached, 



above and ° J 



Nectria be- which are the conidia, and form the mealy bloom 



l Chron 6ard ' of the surface ( Fi g- 134 > The darker clusters, 

 when examined in the same manner, will present, 

 instead of one uniform head, a cluster of smaller globose bodies, 

 closely packed together, or, in some cases, a circle of these dark 

 bodies around a smooth pink centre. These darker bodies are 

 the mature JVectria, which grow at length upon the same stroma, 

 and are the ultimate development of the pink pustules which 

 produce the conidia. Each of the dark bodies is a perithecium, 

 or receptacle, which encloses the fruit, corfsisting of sporidia, con- 

 tained in asci (Fig. 1 3 3 at G). Here, then, we have the Tubercu- 

 laria in the first instance, as a smooth, compact, pink, erumpent 

 pustule, the stem composed of numerous delicate threads con- 

 glutinated together, and sprinkled with minute conidia ; then 

 the darker capsular Nectria originates from the same stroma, 

 these capsules containing the fully-developed sporidia enclosed 

 in asci, — the first stage representing the Tubercularieae family 

 of the Hyphomycetes, the last stage belonging to the Hypocreaceae- 

 family of the Pyrenomycetes. Hence, as the first ,is an im- 



