387 



rable, ami valuable wood, ■wherever light, straight timber, such as hoop- 

 poles, is required." 



The variety of our native forest-trees is very great, and undoubtedly 

 there are many other kinds which are equally entitled to cultivation, 

 with those we have named. Forest-culture is yet in its infancy here, 

 and we should go on experimenting and observing until we learn what 

 are the most profitable and useful kinds. 



YELLOWS OF THE PEACH. 



By TnOisiAS Tayi.or, Microscopist. 



On the 1st of July last I commenced a series of experiments by the 

 moist process with the bark of a peach-tree affected with the yellows. 

 Into five-glass receivers I placed, respectively, a few drops of water, 

 just sufiicient to form a moist atmosphere m each. Into No. 1 1 put a 

 piece of bark affected with the yellows ; into No. 2 a piece of bark from 

 a healthy peach-tree 5 into No. 3 a handful of peach-leaves from the 

 unhealthy tree ; into No. 4 a similar quantity from the healthy tree; 

 and into No. 5 portions of bark from the healthy and unhealthy trees 

 mentioned. All the specimens were secured from the outward atmos- 

 phere. The temperature of the room in which the specimens were kept 

 was frequently at 90° Fahrenheit. These conditions were highly favor- 

 able to the development of such fungi-germs as mature under excess of 

 heat and moisture. Previous to arranging the specimens in the re- 

 ceivers they were examined minutely with a low power, but no signs of 

 fungi were visible. On the 15th day the unhealthy specimens in Nos. 1 

 and 5 exhibited on their external surface a spotted appearance. When 

 viewed by a power of 75 diameters they were seen to consist mostly of a 

 translucent, yellowish-brown, spiral, thread-like fungus known as JSccma- 

 spora. 



Plate 15, figures 1, 2, 

 .3, and 4, represents the 

 first stages of this fun- 

 gus. When a portion 

 about 0.3ths of an 

 inch is placed under 

 an object glass of one 

 inch, and secured in 

 the usual manner by 

 means of a disk, with 

 dilute gum- water, the 

 spiral forms are seen to 

 dissolve gradually, and 

 ultimately to form a 

 yellow stain. On view- 

 ing it with a power of 

 one-eighth, it appears 

 to be a mass of curved 

 spores, resembling in 

 form caraway seeds, 

 but invisible to the 

 naked eye. Each spore 

 has a life-like motion 



Plate 15. 



