June 11, 1897. ] 



SCIENCE. 



909 



the muscle fibres and capsule. In well- 

 stained preparations the complexity of the 

 nerve ending is too great for description 

 here. It may, however, be stated that 

 large medullated fibres ( sensor j'), which 

 supply these structures, divide often into 

 several branches before reaching the spin- 

 dle. Within the spindle they lose their 

 medullary sheath and terminate in band- 

 like structures which are wound around the 

 muscle fibres of the spindles, usually mak- 

 ing a few turns before ending on these 

 fibres. Motor endings also occur on the 

 spindle fibres, more often in the terminal 

 portion of the spindle. 



It may be suggested that, owing to the 

 spiral arrangement of the terminations of 

 the nerve fibres going to the spindle, the 

 simple contraction of the muscle fibres of 

 the spindle and their consequent enlarge- 

 ment might stimulate the nerve fibres. 

 The Protagon of the Brain. E. H. Chitten- 

 den. 



The author reported a series of results 

 obtained by Mr. Frissell in a study of prota- 

 gon. The total amount of phosphorus in 

 «heep's brain by du-ect determination was 

 found to be 1.664 per cent, calculated on 

 the dry solid matter of the tissue. Of this 

 amount 0.234 per cent, existed as protagon; 

 1.14.3 per cent, as lecithin or other like 

 soluble bodies; and 0.213 per cent, in the 

 form of nucleo-proteids, nuclein and inor- 

 ganic salts. The results seemingly indicate 

 that protagon contains but a small propor- 

 tion of the total phosphorus of the brain 

 and that other phosphorized organic bodies, 

 such as the lecithins, are present, preformed 

 in the tissue, in relatively large proportion. 

 If we assume that all of the alcohol-soluble 

 phosphorus of the brain, aside from the 

 protagon, exists in the form of lecithins, 

 we have 72 per cent, of the total phosphorus 

 of the tissue present as lecithin , with only 

 1.5 per cent as protagon and 13-14 per cent, 

 as nucleo-proteids and inorganic salts. Now 



protagon contains approximately 1 per cent, 

 of phosphorus, while distearyl lecithin con- 

 tains 4.13 percent, of phosphorus; hence on 

 the basis of the above figures the dry solid 

 matter of the brain contains as much or 

 even more lecithin than protagon. 



A large number of samples of pure prota- 

 gon prepared from the brains of oxen, sheep 

 and calves showed an average content of 

 phosphorus of 1.12 per cent, thus agreeing 

 closely with Eappel's results. Careful study 

 of these samples showed that, contrary to 

 previous statements, protagon tends to un- 

 dergo cleavage by long-continued heating 

 at 46°C. in 85 per cent, alcohol, a certain 

 amount of an alcohol-soluble (at 0° C.) 

 body richer in phosphorus than protagon, 

 being split oif while the residual protagon 

 obtained by recrystallization at 0° C. con- 

 tained a somewhat diminished percentage 

 of phosphorus. In other words, the sta- 

 bility of protagon is not quite as great in 

 85 per cent, alcohol as is generally stated. 

 On the other hand, the lability of protagon 

 is not sufficiently great to account for all of 

 the lecithins or other soluble phosphorized 

 principles found in fresh brain tissue. Ob- 

 viously these results do not furnish any 

 evidence as to whether the lecithin or other 

 phosphorized bodies found in the fresh 

 brain tissue originate directly or indirectly 

 from the metabolism or cleavage of protagon 

 during the life of the tissue. 

 An Ergometer. J. McKeen Cattell. 



The instrument exhibited was a dyna- 

 mometer made to wi'ite on a kymograph. 

 The maximum pressure of the thumb and 

 forefinger or the movement of a single 

 finger could thus be registered, and a series 

 of movements showing fatigue could be 

 recorded. The curves give the actual 

 amount of work done, the height of the 

 curves being proportional to the pressure in 

 kilograms. The instrument was compared 

 with Mosso's ergograph, and curves were 

 shown in which the movements made in 



