HORTICULTURAL SOCIETY. 347 



world as regards heat, I will clip the following from the St. Louis 

 Republic. 



"Extreme Heat in all Countries. — The following figures show 

 the extreme heat in the various countries of the world: Bengal 

 150° Fahrenheit; Borga, Sahara Desert 153°; Persia 125°; Calcut- 

 ta, India 120°; Central American Republic 129°; Cape of Good 

 Hope, South Africa 105°; Greece 109°; Arabia 111°; New York 

 102°; Spain, Cuba, China and Jamaica, 110°; France, Denmark, 

 Russia and the Sandwich Islands, 100°; England, Ireland and 

 Portugal, 88°; Australia 80°; Scotland 75°; Sweden and Norway 

 65°; Iceland 42°; and Nova Zembla 32°; never above the freezing 

 point." 



Allowing the above figures to be correct, I think the average 

 extreme heat of the world would be a fraction less than 94°, which 

 would show the extreme heat of Minnesota to be several degrees 

 above the average of the whole world. Dame Nature, who under- 

 stands economy as well as any other woman, has fitted certain 

 plants to endure a certain amount of heat, and wben you remove 

 those plants to where it is many degrees warmer, you do so at the 

 great peril of their lives. I observed this particularly in experi- 

 menting with trees from Norway, notably the Norway Maple, which 

 kills with me some seasons to the snow line. This tree has a thin 

 bark. You will note that our table gives Sweden and Norway 65°, 

 which shows too great a contrast between their extreme heat and 

 ours. Were it necessary numberless cases could be cited where 

 plants have been brought to Minnesota from a colder climate, and 

 died here for want of sufficient bark protection. 



The first duty of a physician, when called to attend a patient, suf- 

 fering from an unknown disease, is to attend to the diagnosis. Act- 

 ing upon this supposition the intelligent tree planter, will most 

 naturally inquire after tbat mysterious something that has proved 

 most potent, in consigning so large a percentage of trees planted 

 here, to an untimely grave? Is there anything wrong, or out of 

 tune, in that delicate, and beautiful piece of mechanism, known as 

 the woody cell structure of our hardy Exogens? All this work is 

 so perfect that we could almost compare these plants to certain 

 watches, whose only difference consisted in the difference in thick- 

 ness of the cases. How about the beautiful foliage? Here every- 

 thing is going on with the precision of clock work. How about 

 the cambium layer? Well, now I think we have not only struck 

 the seat of life — but the strong hold of our complaint! Here the 

 new and the half-formed cells, are vainly struggling with all their 

 power and pent-up energy to moisten up, and crowd back the old 

 bark (there is no crowding towards the wood, there all is solid) in 

 order to form the new annual growth. But alas, the extreme heat 

 of this arid clime, has so completely dried up and hardened the 

 too thin bark of the tree, that the life of the cambium layer is so 

 compressed and dried up that it is an impossibility for it to crowd 

 the bark back far enough to form the new layer of wood and bark, 

 hence the tree dies — or at least such parts of the tree where the 

 dry bark has thus compressed the cambium layer. And all for the 



