194 MODERN SCIENCE READER 



ular hormone affects only the other intact side. This 

 experiment and the conclusion drawn from it opens up the 

 interesting question whether perhaps the reproductive hor- 

 mones in general exert their effect through the central nerv 

 ous system. This has not been the usual belief, and the 

 experiments of Nussbaum are open to the obvious objection 

 that the section of the peripheral nerves may have induced 

 certain secondary changes in metabolism which indirectly 

 antagonized the action of the testicular hormone. At 

 present these experiments, so far as I know, have not been 

 repeated with this objection in mind, and it is somewhat 

 gratuitous to criticize the author's conclusions until further 

 work is reported. 



