NOTES AND EXHIBITS. 



415 



These organisms agree in all essential points with those described 

 under the name F. solani Sacc. To test tiie disease, two healthy 

 tubers were planted in contact with portions of diseased ones; 

 and the contact-plants " wilted " in thirty-seven and forty-four 

 days respectively, whereas two others grown side by side, not 

 brought into contact with the disease, continued to grow, and 

 produced healthy tubers showing no sign of disease. The tubers 

 were planted in large flower-pots. (See also Pethybridge & 

 Bowers, Economic Proceedings of the Royal Dublin Society, i., 

 pp.547-558, 1909). 



Drs. Chapman and Petrie showed a series of tubes demonstrat- 

 ing the precipitin reaction with extracts of seeds. Rabbits had 

 been immunized by the intraperitoneal injection of saline extracts 

 of the seeds of Acacia j^ycnantha. The extracts were heated to 

 55°C. for 3 hours before injection. Some results are tabulated 

 as follows. 



In the reactions tabulated, the antiserum was mixed with 

 extracts of the seeds of various species. The extracts were 

 divided into two parts, and one portion heated to 70°C. for one 



