PA 
he Equivalent Mass of a Spring Vibrating Longituclinallyc By 
Alexander Brown (One Chart) . . . . . . 665 
On the " Lines " within Bontgen Interference Photograms. By 
J. Steph. tan der Lingen (Tliree Text-figures, Plates XXXVII, 
XXXVIII). . 671 
Osteology of Palaeornis, with other Notes on the Genus. By E. W. 
_ Shufeldt (Gommunicated by L. Peringuey) (Plates XXXIX- 
XLI) 575 
Note on Apparent Apogamy in Pterygoclium NeivcUgatae. By A, V. 
DuTHiE (Plates XLII, XLIII) V . . \ . \ 593 
• Simple Apparatus for Use in Apphecl Mathematics. By J, Steph. 
VAN DEE Lingen (Two Text-figures) . . . . . . 599 
A New Aloe from Swaziland. By I. B. Pole Evans (Plate XLIV) 603 
The Growth-Forms of Natal Plants. By J. W, Bews (Communicated 
by Professor PL H. W. Pearson) , . - . . . .605 
The South African Rust Fungi. 1. The Species of Puccinia on 
Compositae. By L B. Pole Evans (Plates XLV-XLIX) . 637 
IleatiKg and Cooling Apparatus for Eontgen Crystallographic Work, 
By J. Steph. van dee Lingen (Eight Text-figures) . , . 647 
The Arrangement of Successive Convergents in Order of Accuracy. 
By Alexander Brown . , . . . . . .653 
The Use of a Standard Parabola for Drawing Diagrams of Bending 
Moment and of Shear in a Beam Uniformly Loaded. By 
Alexander Brown. (Four Text=figures) 659 
