SPORE-FORMATION. 



305 



skin, partially covering the spores ; or it may gradually be 

 absorbed during germination. 



Budding can occur at any point on the surface of the swollen 

 spores ; it usually takes place after the wall of the mother- 

 cell has been ruptured or absorbed, but it also occasionally 

 takes place within the mother-cell. After the buds have 

 formed, the spores may remain connected, or they may soon 

 break away from each other. 



Fig. 54. Budding of the spores in Saccharomycfs cerevisice 1. (after Hansen). a, Three 

 snores without the wall of mother-cell ; 6, cell with four spores ; b', the wall of mother-cell is 

 ruptured ; e, cell with four spores, three of which are visible ; c' and c" shows the ruptured 

 wall of mother-cell ; d, cell with three spores ; d"', the ruptured wall of mother-cell ; e-e'"", 

 development of a very strong colony ; f-h, other forms of development ; A", the wall between 

 the two spores has disappeared. 



Certain spores display a very remarkable behaviour (see 

 Fig. 54, e-e'"" and h-h") ; the absorption of the wall separating 

 two neighbouring spores causing them to fuse together. It is 

 possible that the biological significance of this phenomenon lies 

 in the fact that the spores may thus have a greater chance of 

 forming buds under unfavourable conditions. One spore plays 

 the part of a parasite to the other. The amalgamation of the 

 spore is, perhaps, the beginning of the process. 



A similar fusion of spores was observed by Hansen in the 



20 



