56 Trans. Acad. Sci. of St. Louis. 



which on trees 30 to 45 feet tall may number 200 to 300 

 to the tree. 



Attention should also be paid to the management of 

 catalpa coppice during the first year. It has been cus- 

 tomary to leave two or three sprouts to each stool for the 

 first year because of the danger from wind. In case of 

 hail an immediate inspection of the coppice should be 

 made and if the injury has occurred early in the growing 

 season all badly injured growth should be removed. Oc- 

 casionally it will be necessary to cut all the sprouts, but in 

 most cases from 1 to 3 healthy sprouts will remain. At 

 the end of the first growing season, the plantation should 

 again be thinned leaving one sprout to the stool. The rea- 

 son for cutting off sprouts badly injured by hail imme- 

 diately after the storm is obvious. If such sprouts were 

 allowed to remain the growth would be inferior and the 

 stool would be weakened. If injury occurs in the middle of 

 or late in the growing season it is best to leave one sprout 

 to the stool or to leave all remedial work until the end 

 of the season because of the danger from winter killing. 



Hail injury naturally reduces the annual wood incre- 

 ment and in such a storm as the one which occurred at 

 Hutchinson it causes the formation of false annual rings 

 in the species worst affected. Natural pruning of the 

 branches continues for many years after a hail storm 

 has passed; such pruning occurs first on weakened, 

 interior branches and branches deeply wounded, but the 

 pruning continues and has been noted on branches which 

 had been injured 19 years previously. Favorable climatic 

 conditions immediately after the storm assist tree growth 

 in recuperation while a prolonged drouth would greatly 

 increase the damage. 



EXPLANATION OF ILLUSTRATIONS. 



Text-figure. Hail injury to hardy catalpa, experienced ten years 

 before the photographs were made. B shows a false ring. C is fourteen 

 inches below an open wound, but still shows heart-rot. Reduced. 



Plates XI-XVIL— Hail injury to twigs of various forest trees. One- 

 half natural size. 



Issued March 10, 1910. 



