Elementary botany . Fig. of Cycas revoluta. Fig. photograph of same, show-ing female prothallium. sporophyte. Archegonia are developed in this internal mass ofcells. This aids us in deter-mining that it is the prothal-lium. In cycas it is also calledendosperm, just as in thepines. 629. If we cut open one of themature ovules, we can see the en-dosperm (prothallium) as a whitishmass of tissue. Immediately sur-rounding it at maturity is a thin,papery tissue, the remains of thenucellus (macrosporangium), andoutside of this are the coats of theovule, an outer fleshy
Elementary botany . Fig. of Cycas revoluta. Fig. photograph of same, show-ing female prothallium. sporophyte. Archegonia are developed in this internal mass ofcells. This aids us in deter-mining that it is the prothal-lium. In cycas it is also calledendosperm, just as in thepines. 629. If we cut open one of themature ovules, we can see the en-dosperm (prothallium) as a whitishmass of tissue. Immediately sur-rounding it at maturity is a thin,papery tissue, the remains of thenucellus (macrosporangium), andoutside of this are the coats of theovule, an outer fleshy one and aninner stony one. 630. Microspores, or pollen, of cycas.—The cycas plant illustrated in the frontispiece is a female plant. Male plants also exist which have 111 ^ ., . , groups on the under side. 6, group of sporangia; small leaves in the center that bear* open sporangia. (From Warming.). big sporophyll (stamen) of cycas; sporangia in FURTHER STUDIES ON GYMNOSPERMS. 313
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