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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



growth of internal phloem results in filling up the pith cavity with the 

 latter. 



Tho intornal phloem, which runs into the petiole, constitutes there a 

 bicollateral bundle system, but at the base of the petiole it descends 

 through tho xylem as two strands ; from this point upwards the primitive 

 collateral bundle system prevails. No internal phloem in root, or lower 

 portion of hypocotyl, nor in the cotyledons. 



Internal phloem is an acquired characteristic of the plant, probably 

 dovoloped in these long and sometimes twisted stems to supplement the 

 external phloem. — M. C. C. 



Leaf-traces. 



Leaf-traces, Persistence of. By Sir W. T. Thiselton Dyer, 

 K.C.M.G., C.I.E., F.R.S. (Ann. Bot. vol. xv., No. lviii., p. 423).— This is 

 tho first of a series of morphological notes proposed by the author. He 

 observes that interesting specimens frequently come under notice in a 

 large botanical establishment like Kew which, whon relegated to their 

 places in a vast museum collection, do not attract the attention they 

 doservo. Thoso here in question rarely afford the bases for extended 

 research, yet deserve detailed notice, as they often illustrate important 

 theoretical points that may be useful to teachers for lecture illustrations. 

 The present note answers to more than this, and besides being of import- 

 ance to tho phytolithologist is of interest to all who are concerned with 

 wood structure. It is remarked as apparently not generally known that 

 when leaves are more or less persistent the leaf-traces are continued to 

 them through successive annual zones of wood. This fact results in 

 curious structuro which so far as the author is aware, is peculiar to 

 Araucaria amongst Conifers, and he further on observes that " the per- 

 sistence of leaf-traces affords apparently a decisive character for assigning 

 fossil coniferous woods on which they occur, at any rate to the 

 Arancarinea'." It is pointed out that in Pinus a structure may be found 

 which at first sight is similar, but here the "traces" penetrating the 

 annual rings aro not mere loaf-traces, but are the fibro-vascular cylinders 

 of limited branches. Three beautiful photographs are reproduced, two 

 of them showing tho above-mentioned structure of Pinus, and the third 

 that of Araucaria with tho leaf-traces traversing successive annual rings 

 and perforating a ring cut through tangentially. — B. I. L. 



Intka-ovakian Germination. 



Melon, Precocious Germination in a. By Sir W. T. Thiselton- 

 Dyer, K.O.M.G., CLE., F.R.S. {Ann, Bot. vol. xvi., No. 41, p. 149; March 

 1902). — An exceptionally remarkable caso of the abnormal germination 

 of seods within a fruit is here fully treatod, and also illustrated by means 

 of a plate, showing tho fruit cut open, with numerous well-developed 

 seedlings in situ. On the following plate it is conclusively shown, by 

 three drawings of tho removed young plants, that they do arise from seeds, 

 and have not originated from intra-ovarian buds. The author writes: 

 " Tho Melon figured in pi. viii. was kindly sent to me in July 1898 by 

 General tho Right Hon. Sir Dighton Probyn. It had been grown at 



