THE CARE OF SHADE TREES. 



>37 



vitriol, and afterwards with a coating- of tar. It is 

 also very essential that diseased twig's be removed 

 as. soon as seen, and that the fungus be not allowed 

 to produce spores. 



(c) The Pine Fim- 

 fftis, ( Trametes pint. ) 

 (Fig. 1776). — When 

 fully developed this 

 fungus is readily recog- 

 nized as one of the shelf- 

 fungi (Polyporids). — 

 The shelf is irregular- 

 ly triangular in form, 

 two or more inches 

 across, of a reddish 

 brown color, and with 

 the cap concentrical- 

 ly grooved. .As ordin- 

 arily observed the fun- 

 gus is characterized 



by white blotches or expansions on the bark, 

 and by the reddish-brown color oi the dis- 

 eased wood. 



Fig- I775' Perziza willkommii (Larch Canker), (i) showing a jjortion of 

 a branch diseased, (2) two apothecia slightly magnified, (3) an ascus con- 

 taining eight spores, (4) a section of an apothecium greatly magnified, 

 showing the asci and spores in them (b). (i, 2, 3 after Massee, 4 original.* 



Fig. 1776. Trametes pini (Pine Fungus). A 

 section of diseased wood, (a) the pores in which 

 the spores are produced, (b) the affected tissue 

 which is saturated with resin and partially de- 

 composed. (Original). 



Inasmuch as the mycelium gains access 

 to the tree through wounds, and the exter- 

 nal portion does not make its appearance 

 until the mycelial threads are very numer- 

 ous within the tissues of the tree, it is the 

 duty of the owner to treat all wounds imme- 

 diately on discovery, and to remove all trees 

 which show any outward signs of the dis- 

 ease. 



(d) Piue Cone Eungiis [Peridermiiim pini) 

 (F"ig. 1777). This fungus is quite a common 

 form on pines in Ontario. A characteristic 

 feature of the diseased condition of the tree 

 affected is the " resin top," caused by the 

 death of the upper branches through the 

 stoppage of the upward current of sap in the 

 wood. The mycelium is perennial, i. e. , grow- 

 ing- on from year to year. Cells which are 

 attacked lose their normal content, and sec- 

 rete turpentine to such an extent that resin 

 frequently overflows from cracks in the bark. 

 Much irregularity in the growth of the trunk 

 of the tree results from the destruction of 

 the cambium. The stag-e of the fungus 

 which is found on pines is the " aecidial" or 

 cluster-cup stag-e, appearing in early summer 



