252 



ESSENTIALS OF BOTANY 



(6) The surface markings. 



(c) The number, shape, and mode of branching of the appendages. 

 Draw a sac fruit showing the points above mentioned {a — c). 



TV. The Spore-Sacs and Spores. 



Mount in water a few sac fruits under a very small cover-glass 



and press the latter strongly against 

 the slide with a scalpel handle or the 

 square end of a lead pencil until some 

 sac fruits are crushed. Examine with 

 h.p. and note : 



(a) The spore-sacs (asci) escaping 

 from the spore fruits. 



(J) The spores contained in the 

 spore-sacs. Make a drawing to show 

 the asci escaping from the spore fruit, 

 and the number, shape, and size of 

 the spores within the ascus. 



325. Reproduction. — Micro- 

 sphcera is reproduced in two 

 ways. One method is asexual, 

 by means of abundant aerial 

 spores known as conidia, formed 

 by the subdivision of special 

 hyphae into short segments, 

 each of which may grow into a 

 new plant. The other method 

 is sexual, by the union of un- 

 equal gametes to form a sac 

 fruit^ (developed somewhat like 



that of the red algse) which contains many spore-sacs. 

 326. Discussion. — The sac fungi are of interest to those 



who are not specialists in the study of this group, mainly 



1 In most sac fungi it is very difficult to find tlie gametes ; therefore no 

 laboratory work on them is here given. 



Fig. 176. The Morel (Morchella 

 esculenta). (Natural size.)^ 



