. The embryology of Larix. Botany; Larch. 34 ILLINOIS BIOLOGICAL MONOGRAPHS in which they are most prominent. The system which has grown farthest within the gametophyte extends from section a to h. Disintegration of the suspensor of this system is quite advanced in the sections beyond this where the tip of the lower embryo system was in contact with it. The apical cells of the lower system are cut in sections g, h, and i. In both of these embryo systems those two units which adjoin each other in the center by a straight segment of wall are seen to be somewhat larger than the two rows which hav
. The embryology of Larix. Botany; Larch. 34 ILLINOIS BIOLOGICAL MONOGRAPHS in which they are most prominent. The system which has grown farthest within the gametophyte extends from section a to h. Disintegration of the suspensor of this system is quite advanced in the sections beyond this where the tip of the lower embryo system was in contact with it. The apical cells of the lower system are cut in sections g, h, and i. In both of these embryo systems those two units which adjoin each other in the center by a straight segment of wall are seen to be somewhat larger than the two rows which have a single central angle. This is shown particu- larly by sections a, b, and c, and by sections g and h, which transect the apices in both cases. The same condition is observed in Fig. 26, which also represents the second embryo system in its particular corrosion cavity. Section / of Fig. 26 shows the cavity as enlarged by passage of the two systems; the almost completely disintegrated suspensor of the first system is collapsed alongside the second tip. Up to this stage each polarity unit has functioned in close contact with others of the group of four derived from a single embryo system. The tips of the various systems have digested their way through half or three- quarters of the length of the gametophyte, the first system to elongate being most advanced. Soon the tendency toward formation of massive. Fig. 25, a-k.—Serial cross sections of tips of two meta-stage embryo systems within the same gametophyte. Note that the cells which adjoin by the straight central wall are larger and that suspensor cells of the first system are disintegrated at level of contact with the second system (h-k). Collection of May 30, 1933. Fig. 26, a-f.—Serial cross sections similar to those in Fig. 25. The corrosion cavity is shown in /, at a level where the suspensors have collapsed; note also the disintegrated suspensor of an embryo system which preceded the one shown. Fig. 27, a-f.—Serial c
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectbotany
