1892.] NEW-YORK MICROSCOPICAL SOCIETY. 33 



for instance with osmic acid, a proceeding to be recommended for 

 studying the segmental canal. 



8. Rotifera. — The action of hydroxylamine on Rotifers, of 

 which No teas quadricornis, Squamella br acted, and Salpina spini- 

 gera were examined, is also advantageous. After applying a 

 o.i-per-cent solution the cilia of the discs, as well as the muscles 

 of the tail-like foot, become so lame that both wheel-organ and 

 foot are not drawn in when being fixed with picric-acetic acid. 



9. Mollusca. — For Anodonta cygnea and Helix pomatia I recom- 

 mend a -2- to I per cent solution. Both specimens were entirely 

 paralyzed after from ten to twenty hours. The snail had 

 stretched itself out of its house as it usually does while moving in 

 life. The mussel had extended its foot, and the closing muscles 

 of the shell were completely paralyzed. While afterwards fixing 

 in alcohol the animals remained unchanged. 



The aforementioned examples are illustrations of the fact that 

 hydroxylamine possesses a paralyzing power in contractile ele- 

 ments, and that it may be used very successfully in mounting. 



