l68 TRANS. ST . LOUIS ACAD. SCIENCE. 



nite number of bracts, which assume the functions of a calyx and 

 have been sometimes designated as such. Linnaeus, in his Syst. 

 Nat. ed. i, speaks of a calyx ^-phyllus. Their number varies in 

 the difterent species from 3 to 15 or 16, but is fairly constant in 

 the same species. The two exterior lateral bracts are strongly 

 keeled, like those of the sheath of the leaves, and stouter and 

 mostly shorter than the others ; the third is placed on the upper 

 side, towards the axis of the inflorescence ; the fourth on the lower 

 or dorsal side, opposite the supporting bract, and so forth. The 

 innermost ones not rarely exhibit a transition to the anthers, 

 bearing small or incomplete anther cells on the lower part of their 

 back. In P. resinosa and Caitariensis I find the involucral 

 bracts articulated in the middle. 



A table exhibiting the numerical proportion of involucral bracts 

 in the different species, the male flowers of which I could exam- 

 ine, may not be without value. 



3 or 4 involucral bracts I find in P. sylvestris and Pinaster; 



3 to 6 in P. densiflora; 



4 in P. Balfotiriana, Ca?iariensis, and Greggii; 

 4 to 5 in P. ediilis and Parryafia; 



4 to 6 in P. Pinea and P. Halepensis; 



4 to 10 in P. Pyre?iaica: 



5 to 6 in P. 7nonopJiylla: 



6 in P. leiophylla^ JLaricio., and contorta; 



6 to 7 in P. resinosa, moiitana, and Massoniana; 



6 to 8 in P. Strobus, excelsa, Peuce, Cefnbra, rigida, iuberculata, 



muricata, pungens, Banksiana; 

 8 to 10 in P. monticola,Jlexilis, insularis, Chihuahuana^ Thunbergii, 



Laricio var. Pyrenaica, and Aiistriaca, CouUeri, iiiops: 



8 to 12 in /*. T(Eda; 



9 to 12 '\n P MontezumcE and mitis; 



10 in P. insignis: 



10 to 12 in P. ponderota: 



10 to 15 in P. Sabiniana; 



12 in P. Merkusii and Elliotti; 



12 to 14 in P. K/iasia, glabra, and australis; 



14 to 16 in P. Lambertiana and Cubensis. 



The AXTiiEKS consist of two parallel extrorse cells, which 

 open longitudinally on their back ; their connective, heretofore 

 often called a bract, spreads out into a transverse semi-orbicular 

 or almost orbicular, entire or denticulate (in most species of Pin- 



