. The Botanical magazine. Plants; Plants -- Japan. 212 TJTE BOTANICAL MAGAZINE. [Tol. XXXV. >'o 419. Text-figs. 1-13 (X1120) Explanation in text. of the upper two cells contain large and small nuclei, while in the lower two, each possesses a single large one. On the other hand, one or two large nuclei are often found in each divided cell as re- presented in Text-fig. 10—13. Judging from all the features shown in these figures it seems most probable that the nucleus of the fertilised carpogonium detaches a small nucleus during the eary period of carpospore-formation, or the rmcletis of zygot
. The Botanical magazine. Plants; Plants -- Japan. 212 TJTE BOTANICAL MAGAZINE. [Tol. XXXV. >'o 419. Text-figs. 1-13 (X1120) Explanation in text. of the upper two cells contain large and small nuclei, while in the lower two, each possesses a single large one. On the other hand, one or two large nuclei are often found in each divided cell as re- presented in Text-fig. 10—13. Judging from all the features shown in these figures it seems most probable that the nucleus of the fertilised carpogonium detaches a small nucleus during the eary period of carpospore-formation, or the rmcletis of zygote may divide into two halves of equal size, one of winch destined to degenerate, gradually assumes a small size as in the case of the zygotes of Zygophyceas or the gametes of certain diatoms. In any case the small nucleus disintegrates sooner or later, but often persists and divides once or twice before going to degeneration. The nuclear phenomena described above may justify the conclusion that the fertilised nucleus in the carpogonium throws out a part of the nuclear substance : this may be regarded as a primitive form of the reduction division. The recent investigations on the lower members of Nemalionales, as Batrachospermum (5 e), Nemalion (2), Scinaia (lib), which do not produce tetraspore, agree in the inference that the reduction division takes place in the first division of the fertilized nucleus and therefore the cystocarp is gametophytic in character. So in Bangiales, in which the fertilised carpogonium directly becomes carpospores, it is reasonable, as far as we know, to assume that the reduction division occurs in the zygote directly after the fertilisation as in the case of Cliloi'ophycese, Conjugatje, Charace^e etc. And it is highly probable that in Porphyra whose nuclear phenomena are. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectplants, bookyear1887
