50 



to tfiJ^e place entirely independent of nuclear division. 



On tlie upper torder of each of these cells a finger- 

 like outgrov/th of cytoplasm is protruded (fie* HO). The 

 nucleus then divides "by mitosis in the way described for 

 vegetative nuclei of the tetrasporic plant (fig. 110). One 

 of the dau.gliter nuclei reiricdns in the basa-l portion of the 

 cell, the other passes into the cytoplas.'iiic outgrowth, 

 •qhich as usual becomes cut off from the basal portion by 

 the familiar arched membrane (fig. 112), which as usual 

 soon becomes f le,t , Thus is formed a small tvro-celled 

 branch, v/ith a single nucleus in each cell (fig. 113) . The 

 lower may be called the sts,lk cell, v/hile the upper is the 

 tetrasporangiujn or tetraspore mother cell, 



Dujr'ing the growth of this structiire, the stalk cell 

 pushes out another cytopls,smic projection similar to the 

 one first formed. The nucleus divides by mitosis (fig. 

 114), one of the daughter nuclei remaining in the stalk 

 cell, and the otlier passing into the projection, which be- 

 comes cut off like the first. Thus a second tetraspore 

 mother cell is formed on tlie ste.lk cell, A tliird a.nd some- 

 times a fourth motlier cell may be formed in the same way. 

 The first motlier cell may be regc'j:'ded as terminal, the oth- 

 er as lateral. 



In rare cases, two nuclei occur in the primary 



