STERILE CELLS 



19 



Christman, occurring side by side. All the conjugating cells 

 had an upper sterile cell which he calls a "buffer" cell; but 

 the passage of the nucleus only he put down, as others have 

 done, as a pathological phenomenon, caused perhaps by the 

 method of fixing. 



In November of the same year Dittschlag, investigating 

 Puccinia Falcariae, tried to settle the question and decide 

 definitely the function of the spermatia. This Puccinia is an 

 -opsis form, having spermogones and secidia, followed later by 

 teleutospores, but without uredospores. He showed that the 

 cells of the spore-bed of the secidium unite in pairs by the 

 disappearance of not quite all the separating wall. If a sterile 

 cell could be seen at all, it was seen equally on both (Figs. 

 19, 20). 



But this does not militate against its being considered as 

 a degenerate trichogyne : it is certain that the two cells which 



Fig. 19. Puccinia Falcariae. Con- 

 jugation of two female cells to 

 form the basal cell of the ascidio- 

 spore-chain (after Dittschlag). 

 The uppermost cell on the left 

 in a does not belong to the others. 

 Each fertile cell has a sterile 

 cell above it. In b, the hist 

 conjugate division is just com- 

 pleted (Diagrammatic). 



Fig. 20. P. Falcariae. Formation 

 of jecidiospores (after Ditt- 

 schlag) : a, the basal cell; b, an 

 secidiospore-mother-cell ; c, the 

 same in the act of conjugate 

 division (the nucleoli are seen 

 in the middle) ; d, the inter- 

 calary cell cut off. 



fuse are in most cases exactly alike, and therefore, if they 

 represent potential female cells, each of them would naturally 

 be provided with a trichogyne in equal degree, if at all. 



2—2 



