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298 



DE. M. T. MASTEES ON THE MOEPHOLOGT, 

























microsporangium of the Vascular Cryptogams and the anthers oi 



Conifers 



Certain differences may, however, be indicated. Thus in Lyco- 

 podium and Isoetes the sporangia are borne at the base of the 

 upper surface of the leaf, as also in Lepido dendron ; in Selaginella 

 they issue from the stem above the leaf (Goebel) ; whilst in Conifers 

 and Cycads the anthers occupy the lower surface or lower edge 

 of the staminal phyllome. Groebel even points to an analogy 

 between a special growth of tissue on the under surface of the 

 staminal leaf of Cupressus, Thuya, and some species of Juniperus, 

 and the indusium of Ferns. 



Belation of the Stamens to the Leaves. — From what has been 

 already stated it is obvious that the stamens are strictly homo- 

 logous with the foliage-leaves, their position and arrangement 



and 



modified by the 



formation of sporangia, yet intermediate conditions between 

 the leaves and the stamens are met with as monstrosities, aud 



Frenela 

 aens bear 



gradual 



Cu- 



into true peltate stamens with the anthers on the under surface. 

 A similar sequence is obvious in many species of Juniperus, 

 pressus, Larix, &c. In Pinus the stamens are serially continuous 

 with the primary leaves and not with the secondary leaves. Fur- 

 ther details as to the homology of the stamens will be found in 

 the section treating of the malformations of the flower. 



The flowers of Pinus are borne on the shoot of the year and ori- 

 ginate in the axils of spirally disposed perulae just as the fascicles 

 of leaves do, so that one group of stamens has the same relative 

 position as one fascicle of leaves. The leaves of the male flower 

 themselves bear the anthers or microsporangia, while in the 

 female flower, as will be seen hereafter, the sporangia are borne, 

 not on the floral leaves (bracts), but on " a something " which 

 originates within their axils. 



In the Larch the bud-scales are spirally imbricated around the 

 base of a column bearing numerous stamens. These male flowers 

 are placed on the second year's wood and correspond in position 



* 



v 



* 



* Consult Hofmeister, Higher Cryptogamia, ed. Currey (1862), p. 401, 

 Goebel, " Entwick. d. Sporangien," in Bot. Zeit. 1881 ; Outlines of Classificat 

 &c. ed. Balfour, 1887, P. 325. 





















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