1. The freshly excised seminal vesicles of the rat and the guinea pig exhibit rhythmic contractions when suspended in oxygenated Ringer's or Tyrode's solution at body temperature.
2. The seminal vesicles of the rat and the guinea pig exhibit increase in tone and rhythmic contractions on application of epinephrine, ergot, hydrastis, nicotine, pilocarpine, arecoline, and barium chloride.
3. Atropine antagonizes the effects produced by nicotine, pilocarpine, and arecoline on the seminal vesicles of these animals.
4. From the above experimental data, it would be concluded that the seminal vesicles of the rat and the guinea pig possess a motor parasympathetic as well as a motor sympathetic innervation.