46 THE AMERICAN MONTHLY rFeb 



used a sharply differentiated blue-stained 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 theprocesa 

 of spindle formation, the equatorial plate stag? is dis- 

 tinct and shows a sharply bipolar spindle, whose fibres 

 end in deep staining granules at the poles. Pola* radia- 

 tions were not observed at this stage. The chronosomes 

 are densely massed at the equator and number pobably 

 eight or ten. The nucleole may frequently also e seen 

 in the neighborhood of the spindle but reduced in ize. 



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

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

 species of bacterium the Pseudomonas destructan on 

 turnips which produces a white glazy appearance, th tis- 

 sues are reduced to a soft pulpy condition. The bacteium 

 secretes a cytase enzyme which in healthy living thues 

 dissolves the middle lamella and causes the swelling f 

 the cell-wall. On agar-agar it produces a white gi Z y 

 growth and rapidly liquefies gelatin, and during fermi- 

 tation produces a large amount of carbon dioxide. ^_ 

 fection appears always to be introduced at a wound. 



Wilt Disease of Cotton, Watermelon and Cowpej 

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

 17 :) gives an excellent account of a wilt disease occurin^. 

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

 pora vasinfecta (Atk.) Smith 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 cephalosporium stage which are oval to narrowly el- 

 liptical nonseptate, the Fusarium vasinfectum and F. 

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

 3 to 5 septate, (3) chlamydospores; 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 



