THE HAMILTON ASSOCIATION. 



79 



for oviposition. We have had many foolish remedies proposed and 

 as often tried by foolish fruit growers. No less an authority than 

 an American Consul, residing in a Canadian town, recommended, as 

 a sure cure for plum knot, boring a hole in the trunk of the tree and 

 filling it with flowers of sulphur. He said this would circulate 

 through the sap of the tree and destroy the insect of the black knot. 

 Any one cognizant with chemistry or botany will see the foolishness 

 of such a recommendation. 



The plum knot is now known to be a well defined fungus and 

 is galled by mycologists Plowrightia Morbosa. Little spores, 

 corresponding with seeds, float along in the air and alight upon a 

 suitable host, either in the form of a cherry or a plum tree. Soon 

 the hated parasities send down their mycelial branches among the 

 •cells of the wood and derive means of nourishment. Soon they 

 begin to throw up innumerable filaments, called conidia, on the 

 ends of which are borne egg-shaped spores, as shown in the ac- 

 •company ing drawing, figure i. These are summer spores which 







\\;fio^°%<^\ 





Fig. 2.— Cavity of Perithecium, with Ascospores. 

 (May be seen in February with hand-glass.) 



Fig 3. — Asci, containing 

 Ascospores. 



Fig. 4. — Kipe Ascospores. 



Fig. 5. — Ascospores gerni- 

 inat.na. 



