NEW ZEALAND WHITE ROOT-ROT 117 



minute black sclerotia, which eventually give origin to a 

 conidial form of fruit, are formed in the cortex of diseased 

 portions. Next the mycelium becomes dark-coloured and 

 gives origin to globose, black bodies, called pycnidia, con- 

 taining stylospores or minute reproductive bodies in their 

 interior. Finally the ascigerous form of fruit is produced 

 on trunks or stumps that have been dead for some time. 



PREVENTIVE MEANS. Those recommended under 

 Rosellinia necatrix are applicable. 



The following remarks appeared in the Ktw Bulletin in 

 connection with this disease : 



' Stagnant water should not be allowed to remain in the 

 soil, as this favours the spread of the fungus. Finally, in 

 those cases where the fungus has completely devastated 

 large areas, it is probable that such will be deserted as 

 unprofitable, the trees being allowed to lie and rot, and the 

 fungus to spread in the soil. This is disastrous, being in 

 fact a nursery for the development and diffusion of the 

 enemy. It is not the object of this note to suggest whose 

 business it is to prevent such shortsightedness, but to 

 impress emphatically that such a condition of things should 

 not be tolerated.' 



Massee, Kew Bulletin, 1896, p. i, r pi. 

 Wight, Journ. Mycol., vol. v. p. 199. 



5, tip of an ascus after treatment with a solution of iodine, showing the arrangement 

 for effecting the opening or dehiscence of the ascus for the escape of the spores, 

 X3oo; 6, ascospores, one of which is germinating, X45o; 7, brown mycelium with 

 swellings at intervals, XSSD ; 8, a black sclerotium bursting through the cortex of a 

 root, producing several clusters of conidiophores bearing conidia, X 40 ; 9, a single 

 conidiophore bearing conidia at its branched tip, XSQO; 10, free conidia, X 300 ; 

 n, a pycnidium springing from the coloured mycelium, X4o; 12, stylospores 

 developed in the interior of pycnidia, x 300. (From Ke-w Bulletin.) 



