398 MISSOURI STATK HORTICULTURAL SOCIEIY. 



with it its own refutation. If was evident that the cause, whatever it 

 might be, was local, and therefore induced by some special influence 

 operating on particular parts of a tree, wholly independent of the plant 

 itself. In other words, some parasitic action must be the acting power 

 in inducing fire b'ight. Though predisposed this way, we have not 

 hesitated to criticise theories offered in its defense, because we think 

 nothing should be accepted as science that will not bear every attack. 

 Professor Burrill's proposition that the disease was caused by the 

 presence of Bacteria, was fully in accord with our prepossessions ; 

 still we have not hesitated to point out occasionally, weak points; 

 and quite recently, in noticing another paper by Prof. Arthur, we had 

 occasion to observe that there was still left a doubt, whether what was 

 generally known as fire blight, was the disease Prof. Arthur had in his 

 mind. In this paper he has made it clear, that it is the genuine fire 

 blight with which he has been experimenting, though it is also clear 

 that some diseases, or perhaps forms of the real disease, but not the 

 genuine article, are sometimes confused. There is still one point which 

 the Professor does not seem to have observed, and which we think 

 very important to a correct diagnosis of the case, and that is, that the 

 point attacked is really but a very small portion of the branch — an 

 inch or two in most cases — and the rest of the branch is, as he states, 

 killed simply through the destruction in the ascent of the sap. Usually 

 the ringing of a branch, by which the sap would be obstructed, would 

 not result in an immediate blackening of the leaves ; they would grad- 

 ually wither, and finally die away brown instead of black; and this 

 reflection would indicate that there is yet something more than a mere 

 cutting ofi^of the sap supply. Still, the candid reader will have to ad- 

 mit that the results of Professor Arthur leave but little doubt that a 

 species of Micrococus, allied to Bacteria, is at the bottom of all the 

 trouble. It is only its "ways and means" that are yet to be found out. 



BOTANY AND AGRICULTURE. 



Eds. Country Gentleman. — It is a current notion among farmers 

 that the aid which botany is capable of rendering to agriculture is 

 small, both in amount and importance. This notion is co-ordinate 

 with another common idea, that the end and aim of botany is to class- 

 ify and name plants. This idea is the legitimate product of former 

 methods of teaching botany — methods which are still followed in many 

 or most high schools and academies, and probably in some colleges. 

 Under this method the student familiarizes himself with the names of 

 the parts of the flower and leaf, and with this knowledge traces a few 



