it weighs them down and checks the progress of the sap, upon a copious supply of which its own continued existence depends. This remark applies to many parasites which attaching themselves to the younger branches thus commence working out their own destruction almost from the earliest stage of their existence.
The open cups terminating the branches of Beech trees, similar to what is figured at Plate CVT./. 13, are frequently to be met wnth in the woods of Fuegia, and mark the spot where one of these curious vegetables flourished ; by collecting water they soon decay, and the branch is killed below for some little distance, but the mischief caused by so large a parasite is after all very insignificant, and what no healthy Fagus suffers from.
Myzodendron brachystachyum is equally abundant in Hermite Island with M. pmwtulatutn, though from the colour of its leaves, resembling the common forest foliage, it is by no means so conspicuous an object. I met with the male plants much more frequently than the female.
Plate CIII. Fig. 1, a young female plant attached to Fagus Forsteri ; Jig. 2, portion of a female plant with ripe fruit ; Jig. 3, portion of a male stem with flowering and leaf-bearing branches : — of the natural size.
Plate. CV. Fig. 1, portion of a male raceme with bractea and spike of flowers ; Jig. 2, a male flower removed; Jig. 3, vertical section of a stamen ; Jig. 4, transverse section of an anther ; Jig. 5, very young pollen-grains enclosed in the pollinic utricle; Jig. 6. the same more fully developed; Jig. 7, an immature grain removed from the utricle; fig. 8, mature grain of pollen ; jig. 9, portion of a female raceme with bractea and spike ; fig. 10, female flower; Jig. 11, transverse section of ovary, showing the three fissures containing each a seta ; Jig. 12, vertical section of the same ; Jig. 13, ovuliferous column removed from the cavity of the ovarium ; fig. 14, a ripe fruit ; fig. 15, vertical section of the same ; fig. 16, column removed from the same with immature pendulous seed and two abortive ovula ; fig. 17, ripe seed, the albumen sulcated, the broad radicular portion of the embryo enveloped in the trans-parent membrane ; fig. 18, the same with the membrane and funiculus removed; fig. 19, vertical section of an immature seed to show the continuation of the membrane lining the cavity in the albumen in which the cotyledons are lodged; fig. 20, embryo removed ; fig. 21, vertical section of embryo showing the cavity enclosed by the cotyledons : — all more or less highly magnified.
Plate CVI. Fig. 1, a twig of Evergreen Beech with attached germinated seed of M. brachystachyum ; fig. 2, twig of Deciduous-leaved Beech with the same; both of the natural size ; fig. 3, magnified view of the latter; fig. 4, embryo on its first contact with the bark, the cotyledons still enclosed in the albumen; fig. 5, the same attached to the bark, with the albumen removed ; fig. 6, vertical section of the same, shewing the outer coat which spreads over the bark, the sheath which attaches itself to the bark enclosing the cushion-shaped root, and at the upper extremity the cavity enclosing the plumule ; fig. 7, plumule and vascular tissue descending along the axis of the embryo ; fig. 8, longitudinal section of attached embryo and branch of Fagus, shewing the outer coat appbed to the cuticle, the sheath to the corroded bark and the root penetrating the cellular tissue of mesophloeum ; fig. 9, the same more advanced, the radicle having perforated the bark ; fig. 10, a section of parasite and branch at right angles to the axis of the latter, shewing the margin of the sheath finnly attached to the bps of the wound and the radicle appbed to the wood; fig. 11, similar section of another specimen, the edges of the bark revolute, the union of the parasite and Beech very intimate; all more or less highly magnified; fig. 12, cup formed on the branch of a Beech filled by the expanded base of a fully grown Myzodendron, the branches of the latter cut off, thus showing the two series of woody plates ; of the natural size; fig. 13, cup left on the Beech after the fall of a small specimen of Myzodendron : — also of the natural size.
Plate CVII. Fig. 1, longitudinal section through the axis of the branch of a Beech, the cup it forms and its contained parasite ; of the natural size ; fig. 2, vertical section of branch of Myzodendron ; fig. 8, transverse section of the same, showing the two series of woody plates and papillae on the epidermis ; fig. 4, transverse section of the cuticle and one of the pajiillae, showing the cuticle to be thickened and cellular, pushing the epiphlccum inwards before it; fig. 5, transverse section of a portion of the stem, in which the scalariform tissue (c) is crossed by masses
