Aristarchus is also said to have invented two sun-dials, one hemi spherical, the so-called scaphion, the other plane.
They are nearly always absent in the lower Br', Br 2, Br a, Branjaw of the Ecaudata (exceptions in Hemi- chial arches.
In brachy and hemi the aecidiospores are absent, the mycelium from the sporidia giving origin directly to the uredospores; the former possess spermatia, in the latter they are absent.
In the hemi, brachy, micro and lepto forms, which possess no aecidium, we find that the association takes place at various points in the ordinary mycelium but always A, Portion of a young aecidium.
Hydroplzytes and hemi-hydrophytes (aquatic plants).Of marine hydrophytes, there are, in this country, only the grass-wracks (Zostera marina and Z.
Salsola Kali is British, and a hemi-halophyte at least; and it is rather spiny.
The interesting occurrence of certain halophytes and hemi-halophytes on sea-shores and also on mountains is probably to be explained by the past distribution of the species in question.