. Botany for high schools and colleges. Botany. 384 BOTAJYT. Order Xiycopodiaceee.âThe prothallium is known only in one case, viz., Lycopodmm annotinum. It was discovered underground by Fankliauser in 1873, who described it* as a yellowish white, irreg- ularly lobed body, sparingly furnished on its under surface with small root-hairs (Fig. 274,^). In its upper surface the prothallium bears antheridia, which are ^ ^-^ *^ deeply sunken in its tis- sue {an. Fig. 274, A); the spermatozoids, which are numerous, are stout and slightly twisted. The archegonia were only seen after the young plants had
. Botany for high schools and colleges. Botany. 384 BOTAJYT. Order Xiycopodiaceee.âThe prothallium is known only in one case, viz., Lycopodmm annotinum. It was discovered underground by Fankliauser in 1873, who described it* as a yellowish white, irreg- ularly lobed body, sparingly furnished on its under surface with small root-hairs (Fig. 274,^). In its upper surface the prothallium bears antheridia, which are ^ ^-^ *^ deeply sunken in its tis- sue {an. Fig. 274, A); the spermatozoids, which are numerous, are stout and slightly twisted. The archegonia were only seen after the young plants had grown con- siderably (Fig. 274, B) ; they are likewise devel- oped upon the upper surface of the prothal. Hum, and appear to bear a considerable resem- blance to those of the Ophioglos^acecB. The young plant which results from the growth of the fertilized germ- cell is quite simple, but it soon takes on the form of the mature plant. The leaves are crowded in Lycopodium, but are less so in the other gen- era. In many species L;" e, e', two embryos, the larger one with the sporangia are borne r projecting into the neck of the ai'Chego- â xi â¢> f ^â ⢠3 left of the larger embryo is a young ar- ^" ^^° axiis 01 me or-. Fig. 27H â of the spores of SdagineUa. 1, longitudinal section of a niacrospore nf S. Marten- â above the line d is the prothallium, below it the bryo 18 a young 8 i also shown. 2, *' endosperm Its suspeneor nium ; at the left of the larg( chegonium ; several root-hairs are young archegonium of the same species.'not yet open, 3, an archegonium of the same species, with the germ- cell fertilized and dividi d info iwo. .4, a microspore of S. caulescenSy rendered frant-parent, showing the di- vision of the contents into the primordial cells; the small lower cell is the rudimentary prothallium. D, later stage of the same, showing the^arge antheridium filled with sperm-cells ; v. the rudimentary prothal- lium. All magrrifled.âAfter
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1888
