582 RECORD OF MEETINGS OF THE 



The major axis of elasticity always lies parallel to the direction 

 of the fibres. 



3. Refractive Index, 1.57, sufficient, where the associated 

 minerals are pure, to distinguish it by the Becke method from 

 serpentine on the one hand, and from amphiboles, dolomite, 

 etc., on the other. 



4. Birefringence (y — a. =0.020), presenting interference 

 colors of the upper First Order up to sky blue of the lower 

 Second Order, in plates or sections of the usual thinness. 



5. Characteristic strain phenomena; particularly by dis- 

 turbance of the interference figure, examined by convergent 

 light in basal cleavage plates of folia; also by a variable, small 

 extinction angle in sections parallel to the vertical axis. 



6. Optically positive character of the uniaxial figure, in 

 distribution from talc, serpentine, etc. 



7. Occasional twinning, observed in crystals enclosed in 

 limestone. 



8. Certain chemical tests, in confirmation of the optical 

 diagnosis. 



The meeting then adjourned. 



A. W. Grabau, 



Secretary. 



SECTION OF BIOLOGY. 



March 13, 1905. 



Section met at 8.15 p.m., Vice-President Wheeler presiding. 

 The minutes of the last meeting of the Section were read and 

 approved. 



The following program was then offered : 



L. I. Dublin, The History of the Germ Cells in Pedicelli- 

 na americana. 



F. A. Lucas, Whales and Whaling on the Coast of New- 

 foundland (illustrated with lantern slides). 



F. S. Lee, Temperature and Muscle Fatigue (illustrated 

 with lantern slides). 



