22 



BOTANY AND PHARMACOGNOSY. 



formed at the ends of hyphse which rise into the air. The spor- 

 angia are spherical and are cut off from the hyphae by means of 

 a transverse wall which projects upward into the sporangium and 

 which is technically known as the columella (Fig. 13, A). The 

 contents by simultaneous division form numerous one-celled 

 spores, which are discharged by the bursting of the sporangium 

 wall and distributed by air-currents or the wind. As the name 



Fig. 14. Peziza confluens showing stages in the development of ascospores. In the 

 youngest asci (m, r) there is only one nucleus; this divides into two (s); the division is 

 repeated, so that there are 4 nuclei in (t) and 8 in (n). These surround themselves with 

 protoplasm and a cell wall (v, w) but the protoplasm of the mother cell or ascus is not 

 entirely used up. After De Bary. 



of the group to which this plant belongs indicates, it also pro- 

 duces zygospores (Fig. 13, D). These are formed by hyphal 

 branches which ascend from the substratum. The ends of two 

 branches come together, a transverse wall is formed in each 

 branch, the walls in contact are absorbed, the contents unite, and 

 a spore is formed with three membranes, two belonging to the 

 spore proper and the third being formed by the united hyphge. 

 As would be expected, these spores are quite resistant, being able 



