172 TRANS. ST. LOUIS ACAD. SCIENCE. 



but not of much diagnostic importance ; nevertheless it will be 

 necessary in the description of the different species to mention it, 

 and also to state the number of the more prominent secondary 

 spirals, two of which, inclining in opposite directions, are always 

 the most conspicuous. The long cones of/'. Strobus^ excelsa and 

 Ayacahuite, and the short ones of P. edulis and nwnop/iylla, show the 

 y^3 order of scales, and the 3 and 5 spirals are the most prominent 

 ones. P. Lambertia?ia and Sahiniana have the ff arrangement with 

 the 8 and 13 or the 13 and 21 spirals most conspicuous. The 

 intermediate orders of ^\ and f|- are the most common ones ; 

 abnormal orders are extremely rare. 



The cone scales furnish us the most valuable characters for the 

 classification of the species. Their exposed part, not covered by 

 adjoining scales and more or less thickened, has been called the 

 apophysis ; it is rather depressed and terminates in a blunt point 

 in the section Strobus ; in Pinaster it bears its point on the usually 

 more thickened back, the imibo, mostly armed with a prickle, 

 weak or strong, early deciduous (in P. Baifoiiriana^ insignis, Bafik- 

 siana) or stout and persistent (in P. rigida, Tceda, inops, pufigens) ; 

 in some species (P. Sabiniatm, Coulteti) it becomes a thick, long, 

 and often curved or twisted spur. 



The bracts which support the scales remain concealed, but 

 become greatly enlarged and mostly thickened and corky, and 

 help to form lodges for the seeds, which are enclosed between 

 them and the scales. 



The cones generally open their scales soon after maturity, drop 

 their seeds, and fall oft' soon afterwards ; in most cases they sepa- 

 rate at the insertion of the peduncle, but in a few instances {P. 

 ponderosa, P. australis) the peduncle and the lowest part of the 

 axis together with a number of scales remain on the branch. In 

 some species {P. Sabiniana^ Coulteri) the open cones persist for 

 several years on the tree, and in others they remain almost indefi- 

 nitely, so that they are apt at last to be partially enclosed in later 

 layers of wo(jd. Such are P. Panksiana, inops^ pungensi 

 insignis^ muricata, rigida^ and some Mexican species. Most 

 specimens of Pinus contorta retain their cones in this manner, 

 while those of the higher sierras of California are early decidu- 

 ous, proving that this character is not of great specific impor- 

 tance. The persistence of the cones may be connected with the 



