The eye, unaided or armed with a telescope, is able to see, as points of light, stars subtending no sentsible angle.
Bracts of a more general character subtending branches C' of the inflorescence are singularly rare in Gramineae, in marked contrast with Cyperaceae, where they are so conspicuous.
The resistance to slipping of a flat belt on a pulley may be obtained by considering the equilibrium of a small arc of the pulley surface subtending an angle dB at the centre, and having tensions T and T+dT at its extremities.
Each sporangiophore is traversed throughout its length by a vascular bundle connected with that which supplies the subtending bract.
It is thus proved that the sporangiophore is not a mere sporangial stalk, but a distinct organ, in all probability representing a ventral lobe of the subtending bract.