194 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE  [VOL. XII 
"iOr MEXU-DideSt IaVER? or Gee le Gwe retire een eee 68.80% 
Sthior next oldest layere ? 2 vo. os ee ee eee oe 59.70% 
oth -ornextioldest layers) koi act hemes cee ae 54.90% 
rothor next oldesttayen..\. 0 Sy ot eee eee 52.00% 
PV Gsaiier Betis eee eons ee ae ae 50.60% 
PR thbO WS tle ee eres Se Oe Cen ry atin te Ne 48.00% 
Tin to Toten oe Vis EE ens anne ere ee 44.90% 
What part the resins play in the economy of the fungus, how they are 
formed and what is their source are questions of much interest and to 
which as yet in the main no very satisfactory answers have been given. 
Zopf® alone appears to have expressed any view as to the use of 
such an extravagant production of resins and he contents himself with 
the explanation that they are waste products and of no further value 
to the plant. That they occur so abundantly in the fruit-body and to 
such a slight extent in the mycelium (Harz" could find none) indicates 
a striking difference in the metabolic processes of the vegetative and 
the reproductive parts of the plant, and would suggest that they per- 
form some function in the latter. There is no question but that the 
phenomenon is specific, for though resin secretion is shared to some 
extent by some other fungi, more rarely, has it been reported to occur 
in the same way as it does in this. Resin is said to form a layer on the 
surface of the fruit-bodies of Polyporus australis Fr. and P. lucidus, 
which if true is the product of a special superficial glandular tissue; 
in the milk of Lactarii it occurs in drops, and again is the product of a 
special tissue. The colouring matters of Pholiota spectabilis Fr. and 
certain others are reputed to contain resins, and the yellowish secretions 
formed by all parts of Polyporus cinnabarinus possibly may be resinous. 
Harz! considered resin secretion as ‘‘unusual among the fungi’. He 
examined the following Polypores and obtained not a trace of resin: 
‘‘ Polyporus salicinus, P. igniarius, P. betulinus, P. perennas, P. sulfureus, 
P. squamosus, P. zonatus, P. bovinus, P. applanatus, P. hirsutus, P. 
versicolor, P. borealis, P. Schweinitzit, Trametes pint and Daedalea 
quercina’’. , 
That the phenomenon as manifested by F. officinalis, is not unique, 
if infrequent, I hope to show shortly, but emphasis is to be placed on 
the fact that the phenomenon is specific, and that in F. officinalis it is 
developed to a much higher degree than in any other form. The value 
of these secretions to the fruit-body would seem to be protective. Peren- 
nial sporophores to persist from year to year must be immune from 
destructive agencies, and this immunity is secured in various ways, 
sometimes by hard crusts and tough tissues as in the applanatus-group, 
sometimes by stony tissues as in the igniarius-group, and in officinalis 
