136 



HELVELLALES. 



convex. The asci are, comparatively speaking, large, and often contain a great 

 number of spores which escape by the casting off of a lid on the summit of the 

 ascus. Generally living on dung. Ascnbolus furfuraceus, etc. 



Family 6. Helvellales. 



These Fungi have the appearance of clubs, bells, or mushrooms, 

 consisting of an upright stalk bearing a large and fleshy head, on 

 the exterior surface of which the hyinenium is spread. The asco- 



carps are probably gymnocarpic from 

 the beginning, and on this account 

 these plants are placed in a separate 

 family. The development of the 

 nscocarps is unknown. The Morchella 

 (Morell) grows on the ground ; some 

 species are edible. 1 order. 



Order. Helvellaceae. SpnUndca is yellow 

 and club-shaped, and forms "fairy rings " in 

 \voods. Geoylossvm (Earth-tongue) projects 

 above the ground as a black tongue, or as a 

 club-shaped body. Several species are found 

 in meadows and on heaths. Helvetia has a 

 stalk, bearing an irregularly folded head, on 

 the external surface of which is the bypothe- 

 cium. Morchella (Morell, Fig. 130), the stalk 

 bears on its summit the conical or spherical 

 head, the external surface of which is reticu- 

 late and bears the asci. Mitiula. Verpa. 



FIG. ISO. Mnrchelln esculenta: a 

 an entire specimen, about one half 

 natural size ; b longitudinal section 

 through the head. 



APPENDIX TO THE ASCOMYCETES : 

 Family 7. Ascolichenes (Lichen-forming Ascomycetes). 



The Lichens were formerly classed among the Thallophyta as a 

 group quite distinct from the Alga3 and Fungi. Investigations dur- 

 ing the last twenty-five years, however, have conclusively proved 

 that the Lichens are Fungi which reproduce in the same manner as 

 the Ascomycetes, or, more rarely, the Basidiomycetes, and have 

 entered into a peculiar symbiotic relation with Algce, especially 

 the Cyanophyceae and Protococcoideae, with which they associate, 

 and without which they would be unable to exist. The Fungus 

 forms the largest portion of the Lichen, enclosing the Alga with 

 which it may be said to be commensal. The Fungus especially 

 produces reproductive bodies and absorbs the inorganic nourish- 

 ment through the rhizoids, whilst the Alga supplies it with the 

 organic materials. In consequence of this the Lichens, in con- 



