216 STUDIES OF AMERICAN FUNGI. 



ing simply a membrane, and does not possess the coarse meshes 

 present in the veil of D. duplicata. The Figs. 214, 215 represent 

 the different stages in the elongation of the receptacle of this 

 plant, and the rupture of the volva. This elongation takes place 

 quite rapidly. While photographing the plant as it was bursting 

 through the volva, 1 had considerable difficulty in getting a picture, 

 since the stem elongated so rapidly that the plant would show that 

 it had moved perceptibly, and the picture would be blurred. 



In a woods near Ithaca a large number of these plants have 

 appeared from year to year in a pile of sawdust. One of the most 

 vile smelling plants of this family is the Ithyphallus impudicus. 



CHAPTER XVI 



MORELS, CUP-FUNGI, HELVELLAS, ETC.: DISCOMY- 



CETES. 



The remaining fungi to be considered belong to a very different 

 group of plants than do the mushrooms, puff-balls, etc. Neverthe- 

 less, because of the size of several of the species and the fact that 

 several of them are excellent for food, some attention will be given 

 to a few. The entire group is sometimes spoken of as Discomycetes 

 or cup-fungi, because many of the plants belonging here are shaped 

 something like a disk, or like a cup. The principal way in which 

 they differ from the mushrooms, the puff-balls, etc., is found in the 

 manner in which the spores are borne. In the mushrooms, etc., the 

 spores, we recollect, are borne on the end of a club-shaped body, 

 usually four spores on one of these. In this group, however, the 

 spores are borne inside of club-shaped bodies, called sacs or asci 

 (singular, ascus). These sacs, or asci, are grouped together, lying 

 side by side, forming the fruiting surface or hymenium, much as the 

 basidia form the fruiting surface in the mushrooms. In the case of 

 the cup or disk forms, the upper side of the disk, or the upper and 

 inner surface of the cap, is covered with these sacs, standing side by 

 side, so that the free ends of the sacs form the outer surface. In the 

 case of the morel the entire outer surface of the upper portion of the 

 plant, that where there are so many pits, is covered with similar 

 sacs. Since so few of the genera and species of the morels and cup- 

 fungi will be treated of here, I shall not attempt to compare the genera 

 or even to give the characters by which the genera are known. In 



