68 THE AMERICAN MONTHLY [Feb. 



within seven minutes and in twenty minutes more there 

 were two full g-rown bacteria formed from each original 

 cell, althoug-h still attached to each other. At this rate of 

 multiplication 280,000,000,000 would be formed in twenty 

 four hours. They would occupy fully one inch of cubic 

 space. This org"anism is an aerobe and makes compara- 

 tively rapid g^rowth at 8-10 degrees C. The rate of divi- 

 sion increases up to 34-36 degrees C, but above this point 

 It is less rapid. Some growth was obtained at 45 degrees C. 

 As to its parasitic nature, in its early stages the individual 

 bacteria are imbedded in protoplasm, the chlorophyll 

 grains become disorganized, the protoplasmic utricle is 

 broken up and the contents of cell are disintegrated. This 

 germ has the power of eroding the cell-wall and thus 

 dissolves for itself a passage way, which may be brought 

 about by an enzym and it is probable that the perforation in 

 the cell-wall is quickly healed by growth and swelling of 

 the same. They enter the host by means of stomata or 

 accidental punctures. It readily attacks young and partly 

 grown leaves. In addition to an account of the distribu- 

 tion of the disease and the varieties affected they treat the 

 economic aspect. The paper is accompanied by two ex- 

 cellent colored plates and six other plates which show the 

 character of the organisms. (Purdue University, Agrl. 

 Exp. Sta. Bull., No. 59, Vol. VII, March, 1896.) 



Microbes that Make Glucose. — P^veryone knows the 

 service-berry, that decorative shrub that retains its bright 

 red berrieseven in themiddle of winter. Now these berries 

 were the subject of a sort of puzzle about half a century 

 ago. In 1852 Pelouze, examining the juice of service ber- 

 ries that had been left for a long time at the bottom of a 

 dish, discovered a perfectly crystallised substance, very 

 sugary, and having all the properties of glucose. He saw 

 nothing here that was not perfectly natural. We find 

 sugar everywhere, or almost everywhere; there was 

 therefore nothing astonishing in the discovery, and the 

 new sugar was christened sorbine or sorbose. But now 

 began the puzzle. When, a little later, other scientists de- 



