JOURNAL OF MICROSCOPICAL SCIENCE. 



EXPLANATION OF PLATES III AND IV, 



Illustrating Mr. F. Orpen Bower's Memoir " On the Ger- 

 mination and Histology of the Seedling of Welwitschia 

 mirabilis." 



The lettering is uniform as follows :— s. suspensor ; x. collar of embryo ; 

 r. c. root cap ; «jo. apex of root ; r. root ; /. feeder ; e. cotyledon ; e. 

 endosperm ; «. nucleus ; p. I. plumular leaves ; h^. st. hypo-cotyledonary 

 stem ; fvb. fibro-vascular bundle ; scl. sclerencbyma ; ph. phloem 

 ay. xylem ; pr. ph. proto-phloem ; pr. xy. proto-xylem ; ch. cambium ; 

 i. cb. inter-fascicular cambium ; b. s. bundle sheath ; s. b. soft bast ; 

 m. r. medullary ray ; /. lignified tracheids ; r. h. root hairs ; c. t. cortical 

 tiss ; p. pericambium ; m. mucilage. 



Fig. 1. — Mature embryo of Welwitschia. \. a and b. Whole em- 

 bryo, from points of view at right angles to one another, c. Embryo in 

 longitudinal section. 



Fig. 2. — Seedling from a seed sown flat, after twelve days' germination. 

 In A the endosperm is partially removed, the cotyledons and feeder are 

 seen in close connection with it. In B the endosperm removed. *. 



Fig. 3.— Seedling from a seed sown on edge, after eighteen days' ger- 

 mination. A as seen after removing testa. In b the endosperm has also 

 been removed, f . 



Fig. 4. — Seedling six weeks old, showing perforation of testa at dif- 

 ferent points by stem and root. Seed was sown on edge. Nat. size. 



Fig. 5. -^Seedling six weeks old. Seed sown flat. Three cotyledons, 

 the two smaller ones evidently taking the place of one normal one. Nat, 

 size. 



Fig. 6.— Portion of hypo-cotyledonary stem and root with feeder, taken 

 from a seedling of about six weeks. a. Testa removed, endosperm 

 still surrounding the feeder. B. Endosperm removed, remnants of nucleus 

 still attached by the suspensor. c The same in longitudinal section. The 

 feeder and endosperm have contracted, owing to treatment with alcohol. \. 



Fig. 7 and 8. — Seedlings ten and a half weeks old, showing plumular 

 leaves. Nat. size. 



Fig. 9.— Plumule laid bare by removal of one of the cotyledons. 



Fig. 10.— View of apex of the youngest of the specimens in the Kew i 

 collections. \. Sent from Little Fish Bay by J. J. Monteiro, Esq. 



