70 PROCEEDINGS OF THE ACADEMY OF [Feb., 



opening of buds ; but buds of different species of plants if exposed to 

 the same temperature preserve the order of their bud development; 

 but the time interval is very much lessened if the amount of heat is 

 increased. This was exemplified by a double climbing white rose 

 growing against the side of a house with a chimney placed in the 

 outside wall. The heat of the chimney caused the buds over the chim- 

 ney bricks to open at least a week or ten days before those on the rest 

 of the bush showed any signs of development. All of the buds in the 

 rosebush were equally prepared to open, but only those did so which 

 received the stimulating effect of the heated brick surface. 



Experiments of the Second Year. 



The second year of experimentation began with a plan for the 

 enlargement of the scope of the work of the previous year. In order 

 to test the question whether chemical solution could alter the sequence 

 of bud development if the buds were obtained from different geographic 

 localities, and in order to test whether the twigs obtained from south- 

 ern latitudes would or would not respond more or less quickly than the 

 twigs from northern latitudes to the new environmental conditions, 

 a circular letter was addressed to all of the agricultural 'experiment 

 stations and to a few private individuals in the forest-covered portion 

 of the eastern United States from the Gulf States' to Maine. The letter 

 read as follows: 



My dear Sir: — In continuation of a study which I have begun on the influence 

 of chemicals on the opening of buds, I write to ask if you will supply me with 

 twigs of one or several of the following varieties of fruit trees: apple: Baldwin, 

 Early Harvest, Maiden Blush, Red Astrachan, Winesap, York Imperial; cherry: 

 Black Heart, Governor Wood, Morello; peach: Early Crawford, Late Crawford, 

 Oldmixon (free) ; pear: Duchess de An gouleme, Bartlett, Clapp lavorite, Flemish 

 Beauty, Kieffer, Seckel. These twigs I should like cut so as to show the last three 

 years of terminal growth. In addition I should like twigs of the same age of 

 Quercus palustris (the pin oak), IAriodendron tulipifera (the tulip poplar), Populus 

 monilifera (the Carolina poplar), Acer rubrum (the red maple), Msculus hippo- 

 castanum (the horse chestnut), Forsythia viridissima, Tilia americana (the linden), 

 Magnolia conspicua (Yulan magnolia). If not too much trouble please send 

 them so as to reach me on January 15, 1908, when I expect to start all of the 

 twigs received. 



i&o 



This letter is printed in full because it describes the character of 

 the material upon which the experiments were made. Replies were 

 received from eleven institutions widely enough separated from each 

 other, so as to make the results obtained of interest in connection with 

 the acclimatization of plants and with regard to the influence of hered- 

 ity on the general method and time of bud development. The insti- 

 tutions which made reply and the names of the tree twigs sent from 



