STATE HORTICULTURAL SOCIETY. 213 



PROF. T. J. BURRELL'S REPORT ON BOTANY. 



INJURIOUS FUNGI. 



What follows is a partial account of the microscopic, destructive fungi 

 observed at the Illinois Industrial University during the summer of 1876. 

 Few of the observations are deemed complete, but are free from specula- 

 tions or guesses not having an actual basis of known fact : 



The Austrian pines presented a pitiable appearance during the sum- 

 mer and autumn, not improved during the winter, but less noticeable on 

 account of the unlooked-for green at this season. The leaves die first at 

 the outer ends or tips, and gradually turn yellow downward until the whole 

 is dead and drops from the tree. The lower limbs are usually attacked 

 first. Upon examination, small black specks are seen, ultimately raised 

 above the general surface, finally rupturing the epidermis of the leaf by 

 one or more longitudinal slits. Taking now such a leaf to the micros- 

 cope, and, after making an exceedingly thin, transverse section with a 

 razor through a black spot and submitting it to a power of one hundred 

 or more diameters, we shall be rewarded by a most beautiful sight. The 

 black substance is seated in the cup-like hollow, which it has made for 

 itself in the tissue of the leaf, and by its own growth swells out so as to 

 raise and break the epidermis, as stated. At maturity this black material 

 is a mass of spores, originating from threads {jnyceliuni) which traverse 

 the cells of the leaf, and rising in ranks on the concave surface of the 

 little pit or excavation. These spores are peculiar enough, resembling 

 in shape an ordinary ball-club, but more swollen above. The lower 

 handle part is transparent, the enlarged part black with four rings, 

 really transverse divisions of the spore, a transparent conical tip, at the 

 very point of which are three or four ribbon-like streamers half as long 

 as the enlarged part of the spore. There are hundreds of these in each 

 postule or spot. 



But a large proportion of these spots have altogether different con- 

 tents. The general appearance is the same, but instead of the pedantic- 

 looking spores above described, myriads of excessively minute, rounded 

 bodies are produced, which are seen under a high power to have a swing- 

 ing or oscillating motion, as though fastened by a short, flexible string, 

 and trying to free themselves. Such organisms are found in a large num- 

 ber of fungi, especially such as abound upon leaves and twigs, but never 



