206 ANIfUAL REPORT. 



o'clock; therefore, I suggest that we call him forward to address the 

 Societ)' at this time. 



The motion was carried. 



Prof. Seymour then came forward with a number of charts, much 

 enlarged, which were hung up in front in full view, and were used by 

 the Professor in illustrating his remarks before the Society. 



Prof. Seymour. I have nothing especially new to offer, and did not 

 expect to give anything that should go into print, but at the request 

 of your Secretary I have consented to give some points on the subjects 

 of Fungus Diseases of Plants; and 1 would be pleased to receive any 

 practical suggestions from you that we may be mutually benefited by 

 the discussion. 



STRAWBERRY DISEASES. 



The subject of Strawberry Diseases has been treated by Mr. F. S. 

 Earle and Prof. Wm. Trelease has also treated the subject very thor- 

 oughly. Mr. Earle has found ten species of fungi on strawberries. 

 Five of these were species that had never been observed before. Of 

 the ten he finds only about three are specially injurious. White Rust, 

 {Bamularia Tuslanei) is especially destructive and is quite common 

 all over this country, as well as in Europe, where it has been known 

 for many years. Its first appearance on the leaf is seen in little red 

 spots. As those grow older and larger, they become brown, or it may 

 be white, and covered with threads that come through the leaf. This 

 red color comes from a red fluid in the outer cells of the leaf. Mr. 

 Earle finds it to be especially destructive to plants in the latter part of 

 the season, and is more destructive then than at any other time, espec- 

 ially during the fruiting season and afterwards. In the fall the plants 

 have sometimes been found to be so badly diseased as to be almost 

 worthless. The heavy fruiting of the strawberry vines seems to have 

 a good deal to do with the disease. It might seem at first that the 

 fungi are caused by over-fruiting, but I do not think it can be proper- 

 ly said that over-fruiting is the cause of the disease. A man weakened 

 by exposure is more susceptible to disease than if -perfectly healthy, 

 but if he takes the small pox or typhoid fever it is because he is per- 

 haps more susceptible to the germs of the disease than another who is 

 subject to the same exposure and does not contract the disease. If the 

 germs are absent he will not contract the disease in any case. If they 

 are present they will have a better chance to work in the weakened 

 condition of the system. And with the strawberry, in the over-fruit- 

 ing, the plant is exhausted, and if the fungus germ is present it is more 



