122 ASYMMETRIC ANALYSIS 



on different organs while not a single of the ordinarily 

 used organs is strictly specific, as Cannon and Rosen- 

 blueth (1937) pointed out, the results may be regarded 

 as sufficiently reliable if they are repeatedly observed 

 with several different procedures. The most extensive and 

 elaborate investigations were carried out by Bacq (1935) 

 at the Biological Station of Naples. He did not find 

 acetylcholine nor the enzyme which destroys it, choline- 

 esterase, in the tissues of different Coelenterates. The 

 muscles of Annelids and of lower Deuterostomia (Holo- 

 thuria) contained acetylcholine and choline-esterase. In 

 the muscles of Crustacea he found so little acetylcholine 

 that he concluded that the transmission of impulses 

 from the motor nerve to the muscle in these animals is 

 not accomplished by means of this mediator. He insisted 

 on this point at the conference devoted to this problem 

 held in Cambridge in 1937. On the other hand, there 

 are some preliminary communications by Nachmanson 

 (1937), according to which there is some choline-esterase 

 in the ganglions of Crustacea. What is certain, however, 

 is that neuro-effector synapses of the muscles of Crus- 

 tacea are not typical acetylcholine systems, if only for 

 the reason that they are extremely insensitive to the 

 action of externally applied acetylcholine. 



In the accompanying table w^e compare the observa- 

 tions of Bacq with those of Gause and Smaragdova. In 

 six animal groups the two series of independently obtain- 

 ed results coincide. If our suggestions are correct, the 

 differential killing action of optical isomers of nicotine 

 could be employed to detect the presence of the specific 

 receptor characteristic for the acetylcholine system in 

 the neuro-effector synapse of voluntary muscles (Gause 

 and Smaragdova 1939). But further investigations are 

 necessarv for a final conclusion on this problem. 



