Wo r maid. — Further Studies of the ‘ Brown Rot ’ Fungi. /. 317 
a bright blue within the next half-hour, and later it was a still deeper blue. 
C gave a trace of colour at the end of two hours, A and B not until three 
hours. The colour gradually became a little deeper in tone, but it was still 
a pale blue in the tubes of A, B , and C at the end of twenty-four hours, the 
reaction being a little more pronounced with C than with A or B. A corre- 
sponding yellowing appeared in the tubes containing pyrogallic acid, the 
colour again being more intense with D and E than with A, B , and C. 
On the following day the other five cultures were similarly tested, with 
the same general result, D and E readily giving the oxidase reaction with 
guaiacum and with pyrogallic acid, the rest giving a comparatively feeble 
reaction ; C, however, again being a little more active- than A or B. 
None of the isolations used in this experiment had been previously 
tested for the oxidase reaction, so that the result is further evidence in 
support of the conclusion previously arrived at, that the forms mali and 
pruni can be distinguished in the laboratory by applying comparative tests 
for secretion of oxidase in liquid culture media. In this connexion the fact 
that the two isolations of forma mali used in the above experiment were 
obtained from specimens received from such widely separated counties as 
Kent and Ross-shire is not without interest. 
V. ‘ Shoot-Wilt 5 and ‘Wither-Tip 5 compared. 
The disease described in the present paper differs from ‘ Wither-Tip 5 
primarily in the fact that in the former the short lateral shoots are affected, 
in the latter the long terminal shoots ; both kinds of shoots bear leaves only 
and develop from buds produced on long shoots in the previous summer. 
The difference is not an absolute one, since under certain conditions, 
particularly if the terminal shoot is injured or checked in growth, the lateral 
shoots are induced to elongate and are then subject to ‘ Wither-Tip 5 . 
Although the two have thus much in common, the disease at present 
under consideration shows certain features that do not appear in typical 
cases of ‘ Wither-Tip 5 . The wilt of the short shoots is noticeable early in 
the season, i.e. about the time the trees are in bloom, whereas ‘Wither-Tip’ 
is not conspicuous until later in the season, when the terminal shoots have 
reached a length of several inches. In ‘ Wither-Tip 5 the disease is con- 
fined to the current year’s growth, since further extension of the fungus 
ceases before it reaches the older parts of the twig ; the axis of a lateral 
shoot, on the other hand, is usually so short that the fungal hyphae pass 
almost directly from the infected leaves to the twig bearing the shoot and 
a canker of the bark and wood round the insertion of the shoot very 
frequently results, together with the gummosis of the young xylem elements 
as described above. 
In both forms of disease Monilia fructifications may appear on the 
leaves, under favourable conditions, during spring and summer, but as a rule 
