Notes and Brief Articles 



283 



cell at the level of the clamp. The apical cell so formed has a 

 plus and a minus daughter nucleus. The hasal cell has a minus 

 nucleus and the young clamp has a plus nucleus. Fusion now 

 occurs between the basal cell and the young clamp and the nu- 

 cleus of the clamp passes into the basal cell so that it too has a 

 minus and a plus nucleus. 



At times the clamp fuses with what will be the future basal 

 cell before the nuclei divide, so that the apical and basal cells both 

 contain two nuclei before cell division occurs. Intercalary cells 

 may also divide and the nuclei here also undergo conjugate divi- 

 sion. Conjugate nuclear and cell divisions are always associated 

 with the formation of a clamp connection. Occasionally, how- 

 ever, a reversion of the characteristics of secondary mycelia to 

 those of the primary type occurs ; in which case, cells are found 

 in the secondary hyphae which have no clamps and which pro- 

 duce oidia. 



This admission by Miss Bensaude makes us feel that the classi- 

 fication of the mycelia has no real basis, for uninucleated cells 

 and binucleated cells with clamps have been observed by others, 

 and Kniep (191 5) claimed that the binucleated condition of the 

 cells once established, it is never interrupted. The point, un- 

 doubtedly, needs further study. 



Miss Bensaude's problem is a difficult one. Her work is highly 

 commendable, for it clearly shows the necessity of working with 

 cultures from single spores. Her figures are undoubtedly faith- 

 ful representations of her preparations, but her interpretations 

 are not adequately supported. The results she presents are theo- 

 retical possibilities but the evidence falls short of being convinc- 

 ing and conclusive. 



Michael Levine 



