78 ADRENALIN IN ANNELIDS 



of the sinus, and that any secretion, such as that of adrenalin in the 

 chromaffin cells, could thus reach the circulation of the segment in 

 which the ganghon lies. 



An attempt was made to obtain an extract of the central ganglia 

 in order to see whether any physiological reaction could be obtained 

 similar to that of adrenahn. The nerve cords of a number of leeches 

 were removed under a dissecting microscope by opening up the ventral 

 sinus and cutting through the lateral nerves as near to the ganglia 

 as possible. Each ganglion was then cut away from its connectives 

 and placed immediately in a watch-glass which was kept in a des- 

 iccator. About 400 gangHa were thus collected. As the amount of 

 material when dried was extremely small, the physiological test de- 

 cided upon was the inhibition of the virgin uterus in the cat. I was 

 fortunate in obtaining the assistance of Dr. H. H. Dale in carrying 

 out the test. The uterus was suspended in Ringer's solution and a 

 sufficient amount of histamine was added to the bath to give it a 

 strength of 1 in 3 millions, in order to produce tone and rhythm. 

 The result of the experiment is shown in Fig. 2. An extract of the 

 dried gangHa was made by grinding them up with sand in 2 cc. of 

 Ringer's solution. The bath in which the uterus was suspended 

 contained 50 cc. of Ringer. At A the 2 cc. of extract were added to 

 this bath, with the result that a distinct lowering of tone and dimi- 

 nution of rhythm took place. Similar experiments with extremely 

 dilute solutions of adrenahn gave a much stronger inhibition when 



r-T— mg. was added to the 50 cc. bath, but a smaller inhibition when 



mff. was added; the extract therefore contained an amount of 



20,000 ^ 



1 1 



adrenalin lying between 7"^ and TfTT^ mg. This experiment sup- 

 ports the conclusion that the chromaffin reaction of the six nerve 

 cells in the ganglion of the leech is due to the presence of adrenalin 

 in them. It confirms a statement of Biedl that he has been able to 

 obtain the biological tests for adrenahn from these cells. I have, 

 however, been unable to find any detailed description of his 

 experiments. 



