. Botany for high schools and colleges. Botany. MEPATtGM 347 by the rapid growth of the surrounding tissue of the thallus {A, B, and C, Fig. 333). In other cases the antheridia are de- veloped in great numbers upon special branches, as in Marchantia, which has a large " antheridial disc" {A and B, Pig. 331, Jiu), in whose upper surface are to be found many imbedded anther- idia. That the an- theridia are actu- ally external in this case also, be- coming apparent- ly internal by the growing up of the surrounding tis- sues, is well shown in Fig. 333. In still other cases {, in Jung
. Botany for high schools and colleges. Botany. MEPATtGM 347 by the rapid growth of the surrounding tissue of the thallus {A, B, and C, Fig. 333). In other cases the antheridia are de- veloped in great numbers upon special branches, as in Marchantia, which has a large " antheridial disc" {A and B, Pig. 331, Jiu), in whose upper surface are to be found many imbedded anther- idia. That the an- theridia are actu- ally external in this case also, be- coming apparent- ly internal by the growing up of the surrounding tis- sues, is well shown in Fig. 333. In still other cases {, in Junger- ') the antheridia are in the axils of the leaves, and occur singly or in groups. 453.—The ar- chegonium first appears as a simple papilla, composed of a single cell, which, by subdi- vision in vajdous. Fig. 235.—The archegonia, and origin of the eporogo- nium oiMarehantla polymorjjha. I. and //., young arche- fonia ; e, germ cell; at, lowest cell of axial row of cells. 11. and /F., the same after the formation of a central canal by the absorption of the axial row of cells in the neck. the same when mature and ready for fertiliza- tion. F/., the base of a fertilized archegonium, the germ-cell,/, divided into two cells by a diagonal partition, VII., later stage of the same, ahowmg further division of the germ-cell, /. and the beginning of the growth of a perianth, pp. VIII., still later stage of the same, the perianth, pp, now enclosing the archegonium; x, the withered neck of the archegonium. IX., tne unripe sporo- gonium, enclosed in the old waJls of the archegonium, now called the calyptra, a; f, wall of sporogoniura ; St, the short, undeveloped stalk of the sporogoninm. Inside of the sporogonium are the young elaters arrange 1 radially, and between them are the spores. /. to VIII. X 300; IX. about 30.—Alter Sachs. directions, gives rise to a more or less. Please note that these images are extracted from scanned page images that may have been digitally
Size: 1202px × 2078px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1885
