1918] DUFRENOY—PINE NEEDLES 451 
In the pifadas of Gascony, many of the needles which are infected 
in early spring by the aecidium of Coloesporium senecionis (Peri- 
dermium oblongisporum Kleb.) dry up and fall in summer. The 
“maladie du rouge” is very prevalent and the most important 
cause of the falling of needles, bringing ruin to many pine nur- 
series. It derives its name from the red patches that appear and 
spread on infected needles. It is due to several species of Asco- 
Fic. 27 Fic. 28 
Fics. 27-28.—Fig. 27, transverse section of juvenile leaf: s, A hair; 
hr, hypodermal resin canal; fig. 28, staminate cone of P. maritima: basal part, pro- 
tected from sea wind by ri ridge j in dune, normal and fertile (s, scale; f, ake upper 
part, exposed to sea wind, sterilized; collected on sand dunes of Arcachon, May 1917; 
note gradual reduction and sterilization of flowers from base upward 
mycetes: Lophodermium pinastri, which is the most common on 
several species of pine (P. sylvestris, P. Pinea, P. maritima); 
Hypoderma pinastri, the conidial form of which was observed by 
DuFrrRENoy on P. maritima; and H. strobicola, observed by FRON 
on P. Strobus. 
Conclusion 
Morphological variations are but the result of physiological 
variations (9). The different forms of the different phyllodes of 
pines, juvenile leaves, scale leaves, fertile leaves (4 and & flowers), 
