46 THE AMERICAN MONTHLY [Feb 



used a sharply diflfereutiated blue-atained chromatin net 

 may be seen lying in a clear nuclear sap, a red stained 

 nucleole, and a bounding membrane. The nucleus now 

 divides, but the figure is too minute to study the process 

 of spindle formation, the equatorial plate stage is dis- 

 tinct and shows a sharply bipolar spindle, whose fibres 

 end in deep staining granules at the poles. Polar radia- 

 tions were not observed at this stage. The chromosomes 

 are densely massed at the equator and number probably 

 eight or ten. The nucleole may frequently also be seen 

 in the neighborhood of the spindle but reduced in size. 



White Rot of the Turnip. — M. C. Potter (Univ. of 

 Durham, Phil. Soc. 1899, separate) has described a new 

 species of bacterium the Pseudomonas destructans on 

 turnips which produces a white glazy appearance, the tis- 

 sues are reduced to a soft pulpy condition. The bacterium 

 secretes a cytase enzyme which in healthy living tissues 

 •dissolves the middle lamella and causes tlie swelling of 

 the cell-wall. On agar-agar i.t produces a white glazy 

 growth and rapidly liquefies gelatin, and during fermen- 

 tation produces a large amount of carbon dioxide. In- 

 fection appears always to be introduced at a wound. 



Wilt Disease of Cotton, Watermelon and Cowpea. 

 Dr. Erwin F. Smith (Bull. Div. of Veg. Phys. and Path. 

 17 :) gives an excellent account of a wilt disease occuring 

 on cotton, watermelon, and cowpea due to the Neocosmos- 

 pora vasinfecta (Atk.) Smitli with two varieties, one on 

 cowpea and one on watermelon. It produces bright 

 beautiful red perithecia in the ascomycetous stage. The 

 conidial fruits are represented by the (1) microconidia 

 or cephalosporiuni stage which are oval to narrowly el- 

 liptical nonseptate, the Fusarium vasinfectum and F. 

 niveum. The (2)macrocouidia or Fusaria stage with spores 

 3 to 5 septate, (3) cliL-anydospores; these are globose thin- 

 walled, smooth and in mass are brick red. The fungus 

 is an active parasite and destroys a great many plants by 



