Transactions of the Royal Society of New Zealand . Fig. g Fig. 7. Transverse cotyledon, M. excelsum, passing through midrib: a, upper; b, lower epidermis ; c, xylem ; d, phloem. X 8 and 9. Hypocotyl below entry of cotyledon-traces. X 150. side of the axis in threes. These appear to fuse together, the xylems firstof all. A single cotyledonary trace enters from each cotyledon. Onits entry the phloem is found in two masses on either side of the xylem ;the elements travel towards the centre,and leave the protoxylem exarch, as inPeperomia amplexifolia, P. tithymaloides,and P. maculosa. Th
Transactions of the Royal Society of New Zealand . Fig. g Fig. 7. Transverse cotyledon, M. excelsum, passing through midrib: a, upper; b, lower epidermis ; c, xylem ; d, phloem. X 8 and 9. Hypocotyl below entry of cotyledon-traces. X 150. side of the axis in threes. These appear to fuse together, the xylems firstof all. A single cotyledonary trace enters from each cotyledon. Onits entry the phloem is found in two masses on either side of the xylem ;the elements travel towards the centre,and leave the protoxylem exarch, as inPeperomia amplexifolia, P. tithymaloides,and P. maculosa. The phloem massesultimately fuse with the plumular phloem;as the xylem from the plumular tracesmoves also towards the centre a centralplate of xylem is formed ; and we find atypical diarch structure. But the plumu-lar xylem may be very small in amount ;so that, as in Piper cornifolium, the centralplate is composed mainly of elementsderived from the cotyledonary in one seedling examined the platewas composed mainly of elements derivedfrom
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscience, bookyear1911
