Smithsonian Report, l')4l. -Thimann 



Top, Canada hemlock. Left to right, 400, 100, and mg. auxin per liter for 24 hours. 



Middle, Canada hemlock, variety pendula. Left to right, 100, 50, and mg. auxin per liter for 24 hours. 



Bottom, Blue spruce. Left to right, 400, 200, 100, and mg. auxin per liter for 24 hours All photographed 



after 9-10 weeks in peat-sand medium. (From Thimann, K. V., and Delisle, A. L., Journ. Arnold 



Arboretum, vol. 20, pp. 116-136, 19.39.) 



