THE ADRENAL BODIES 97 



Such cells were later described in a large number of leeches 

 Gnathobdellidse and Rhynchobdellidse and still later Poll 

 gives a description and some very convincing drawings of these 

 chromaphil cells in Nephtkys scolopendroides. As regards the 

 yellow cells of Pontobdella described by Leydig, these appear 

 to be of a different nature. As pointed out by Poll, we are 

 sadly in need of another micro-chemical test for adrenin- 

 containing tissues. If the ferric -chloride reaction could be 

 used for histological purposes, it would clear up many doubtful 

 points. 



Roaf and Nierenstein have expressed their belief that there 

 is a substance in the hypobranchial gland of Purpura lapillus 

 which is allied chemically and physiologically to adrenin. But 

 the identity of the substance with adrenin has been denied. 

 Roaf has recently returned to the subject and finds that in 

 Purpura lapillus there are associated (1) a pressor substance 

 in the strip of tissue adjacent to the so-called rectal gland ; 

 (2) a purple -forming material in the same area ; (3) a collec- 

 tion of bichromate-reacting granules also in the same situa- 

 tion. The .inference is that these, if not identical, are at 

 least functionally associated. 



It is curious that, so far as I can ascertain, Poll and Roaf 

 make no reference to each other's work. It is clear that the 

 structures they respectively describe are quite different from 

 one another. The tissue described by Roaf is not apparently 

 connected with the nervous system, while the chromaphil 

 cells of vertebrates are always intimately related to the 

 sympathetic. The cells described by Poll are, on the other 

 hand, within the central nervous system, and, at any rate, 

 bear a very great resemblance to the cells which are familiar 

 to us in the vertebrate sympathetic. 



Further investigations on the chromaphil tissue of annelids 

 have been carried out by Biedl and by Gaskell. Both these 

 authors claim that they have succeeded in bringing about 

 inhibition of the virgin uterus of the cat by means of an extract 

 of the ganglia of Hirudo medicinalis. The cells described by 

 Gaskell are nerve-cells which give a chromaphil reaction and 

 which he thinks are the common ancestors of both the chroma- 

 phil and the sympathetic systems of vertebrates. This is not 

 in accordance with the views of Giacomini. 



