INDEX 
TO THE 
PHILOSOPHICAL TRANSACTIONS 
FOR THE YEAR 1881 . 
A. 
Abel’s theorem. , 713, 751. 
Abney (W. de W.) and Festing (E. R.). On the Influence of the Atomic Grouping in the Molecules of 
Organic Bodies on their Absorption in the Infra-red Region of the Spectrum, 887. 
Absorption in the infra-red region of the spectrum, 887. 
B. 
Baber (E. C.). Researches on the Minute Structure of the Thyroid Gland, 577 (for contents see 
p. 577). 
Batrachia, structure and development of the skull in the, 1 (see Parker). 
Bessel’s functions in connexion with Riccati’s equation, 762, 819. 
Bottomley (J. T.). Ou the Thermal Conductivity of Water, 537. 
C. 
Calamostacbys Binneyana, 298. 
Cayley (A.). Addition to Mr. Rowe’s Memoir on Abel’s Theorem, 751. 
Coal-Measures, fossil plants of, 283 (see Williamson). 
Cochlea of Ornithorhynchus, compared with that of Mammals and Bird's, 267. 
Conductivity , thermal, of water, 537. 
Crookes (W.). On the Viscosity of Gases at High Exhaustions, 387 (for contents see p. 387). 
Cubic curve in space, on the forty-eight coordinates of, 375. 
Curvilinear coordinates, conjugate, in three dimensions, 611. 
