HIGHER FUNGI 



125 



antheridium, which is cut off by a partition wall. The walls 

 between the two organs are dissolved and the male nucleus passes 

 through the opening formed wanders toward the egg nucleus with 

 which it fuses. Immediately after fertihzation, the oogonium begins 

 steady growth, and some of the outer cells formed become the cover 



Fig. 39. — Diagrammatic representation of the development of the ascogenous 

 hyphal system. {After Claussen.) 



cells of the perithecium. But ascogenous hyphae are formed, which 

 contain two nuclei, then four nuclei by division with karyokinetic 

 figures. Two of the nuclei wander to the curved side and this is cut 

 off by two partition walls to form the binucleated penultimate cell, 

 which becomes the mother cell of the ascus. The two nuclei of the 



