Canadian Forestry Journal, March, ipi6. 



437 



planting of the sets, fifty to sixty 

 feet in height and three and a half 

 feet in girth." One at fifty-five 

 A-ears was a hundred and one feet 

 in height and eighteen feet in girth. 

 To those interested in pulp wood, 

 the natural thing to do is to think of 

 spruce and poplar. Spruce is slow 

 growing and slow to flower (30 to 

 40 years under forest conditions) 

 and so far as I know, there have 

 been no crossings of spruce at- 

 tempted. A\'ith poplar, on the other 

 hand, the trees grown from slips 

 will flower when about four years 

 old. This and the fact, that the 

 flowers are easy to artificially fertil- 

 ize as compared with spruce and 

 similar trees, make poplar a much 

 easier tree to handle experimentally. 



Effect in Poplars. 



There are a few cases of crosses 

 which have been made between var- 

 ieties of poplars and you will be in- 

 terested to learn regarding them. 



There is a wonderful hybrid pop- 

 lar growing at Metz, Germany, 

 which in 1913, when eighty-one 

 years old from seed, measured a 

 hundred and fifty feet in height and 

 twenty-five feet in girth at five feet 

 above ground and at last accounts 

 seemed to be still growing steadily. 

 A younger tree, a cutting from the 

 tree just mentioned, was at forty- 

 three years old, a hundred and fort}' 

 feet high, and sixteen feet in girth, 

 and would cut 7,000 board feet of 

 lumber. In the case of another hy- 

 brid poplar, which was unrelated to 

 those just mentioned, the cutting 

 was forty-five feet in height and 

 eight inches in diameter fifteen years 

 after planting. This was on a poor 

 shallow soil. These were accidental 

 hybrids. There is no reason to think 

 they are ,the most rapid growing 

 that would be obtained if crosses 

 were made systematically. 



Ten Feet in 2/ Months. 



Henry by artificial fertilization 

 obtained a hybrid poplar that in 

 twenty-seven months was ten feet 



one inch in height. One appreciates 

 what this means when one considers 

 that many forest trees at twenty- 

 seven years, instead of twenty-severi 

 months, are scarcely more than a 

 third this height. 



Given a single satisfactory tree, 

 there is no difficulty in getting in a 

 few years thousands, or even mil- 

 lions, of trees from it, each as good 

 as the original hybrid. 



The practical solution of the prob- 

 lem will be to get together speci- 

 mens of the L\vent3^-five or thirty 

 varieties of poplar known in this 

 country and abroad, cross them, 

 grow the resulting hybrids, and test 

 the woods ol)tained from these hy- 

 brids for pulp-making c[ualities. 

 From the results obtained, choose 

 the hybrid that in growth of wood, 

 quality of wood considered, is the 

 best and, using this tree as a source 

 of stock, reforest the cut over pulp 

 wood lands. 



Cost of Exferiuicnts. 



To carry out such a programme 

 will take skilled scientific workers 

 and some time. As I estimate it, 

 it will require, to cover all expenses, 

 about $7,000 a year for six or seven 

 years to get and test the possible 

 hybrids and to get seedlings or cut- 

 tings to begin actual planting on 

 forest lands. 



In this connection it may be worth 

 calling the attention of the younger 

 generation of paper-makers to the 

 fact, that twenty-five years ago, 

 poplar was more used than spruce 

 for making ground wood pulp for 

 news paper. It is well known that 

 to-day poplar is our most used wood 

 for soda pulp. Judging from an 

 article of a month ago in the Pulp 

 and Ppper Magazine of Canada 

 there is a possibility of poplar be- 

 coming in the near future an impor- 

 tant wood for use in sulphite mills, 

 if it can be had at a less price per 

 cord than spruce. This sulphite 

 pulp from poplar is obtained in good 

 yield and meets the class of needs 

 met in England by esparto pulp. - 



