Scientific Proceedings. 



117 



benzoic acid given to rabbits is greater on the first day of the 

 administration during a fasting period than on subsequent days. 

 Whether the glycocoll is combined with carbohydrate as an amino- 

 sugar, as Luthje imagines, or not, it is evident from the several 

 experiments that no permanent synthesis takes place. Glycocoll, 

 therefore, behaves in much the same way in metabolism as does 

 gelatin. 



82 (225) 



An hydrodynamic explanation of mitotic figures. 

 By ARTHUR B. LAMB (by invitation). 



[From the Havemeyer Chemical Laboratory \ New York University.^ 



The distinctly polar arrangement of the chromatin substance 

 about the astral centers in dividing cells, combined with the pro- 

 nounced curvature of the astral rays and of the spindle fibers, 

 have demanded the assumption of some polar force as universally 

 operative. On such an assumption it is of course necessary to 

 assume further that astral centers represent either opposite or like 

 poles. On the alternative of opposite poles, we should expect, 

 with any force so far proposed, a configuration of astral rays 

 simulating that of iron filings between opposite magnetic poles, 

 coupled with a mutual attraction of the astral centers. On the 

 other alternative, we should similarly expect a configuration of 

 astral rays and spindle fibers simulating that of iron filings between 

 like magnetic poles, coupled with a mutual repulsion of the astral 

 centers. Actually, we have neither of these conditions, but instead, 

 a configuratian like that of iron filings between opposite magnetic 

 poles and at the same time an apparent repulsion between the astral 

 centers or the centrosomes. 



This is not the case with the forces of attraction or repulsion 

 existing between bodies oscillating or pulsating in a fluid medium. 

 More specifically, if two spheres are pulsating synchronously and 

 in opposite phase, or oscillating synchronously and in the same 

 phase, they will repel one another, but at the same time the field 

 between them will simidate the configuration of iroit filings betiveen 

 opposite magnetic poles} 



1 See Bjerknes' text-book, " Hydrodynamische Fernkrafte," J. A. Barth, Leip- 

 zig, 1902. 



