Journal of Proceedinrfs. Ixix 



Tlie l^resident, at the conclusion of the paper, said he was sure all the 

 members of the Club would agree with him that they were much indebted 

 to their Vice-Prosident for his admirable treatment of a subject which 

 presented so many points of interest to thfm all, and one which Mr. 

 Fitch had for many years made a special study. In addition to the 

 important list of the galls of their county, the author had given a most 

 valuable introduction containing a resmne of the different theories of the 

 cause of galls which had been propounded ;" and he (the President) felt 

 sure that a subject which appealed to so many different classes of their 

 members — to their zoologists, botanists, and general biologists — would be 

 warmly taken up. The President thought that the best compliment they 

 could pay to Mr. Fitch would be to discuss the subject thoroughly ; and 

 in inviting observations upon it he felt confident that the author would 

 be only too glad to reply to any questions that might be put to him. 



A long discussion then took place with reference to various points in the 

 history of galls touched upon in the paper. 



Dr. Pearce took exception to Sir James Paget' s opinion that there was 

 an analogy between the growth of galls on plants and the morbid pro- 

 cesses exhibited in many diseases of the human subject, but before 

 considering that point, he wished, as a new member of the Club, to 

 express the pleasure with which he had listened to Mr. Fitch's jmper ; he 

 had never heard a more complete bringing together of a multitude of facts 

 and observations than that which the essayist had presented to them that 

 night. Pieturning to the allusion in the paper to the inoculation of the 

 human system with the several " viruses " — such as variola, vaccina, 

 cancer, syphilis, and other inoculable and constitutional diseases — he 

 understood the essayist to state that the formation of galls in the vege- 

 table kingdom bore a resemblance to the action of the said viruses in the 

 animal system. In his (Dr. Pearce's) opinion a distinct line must be 

 drawn between the two classes of phenomena ; and while there was some 

 dispute amongst biologists as to whether galls were due to the mechanical 

 UTitation of the egg, or to the introduction with it of some stimulating 

 fluid by the insect which tended to produce the galls, there was still no 

 real analogy between their production and the results following an inocu- 

 tion with animal virus. On a tree the egg of a gall insect might be 

 immediately productive of a morbid growth — a gall limited to a given 

 spot, and not affecting the life or disturbing the general condition of the 

 plant. In the case of inoculating, whether with variola (small-pox) or 

 vaccina (cow-pox), a process of fermentation is set up, permeating and 

 affecting the whole system — giving evidence of its existence after the lapse 

 of a certain fixed number of days, by tlie appearance in vaccina of a 

 vesicle at the seat of inoculation, or, as in the case of variola, developing 

 on every part of the surface of the body hundreds of vesicles, which ulti- 

 mately become pustules. He further remarked that there did not reason- 

 ably appear to be a resemblance between galls in the vegetable kingdom 

 and certain skin diseases incident lo the gt'iius homo, children more 



