98 THE DUCTLESS GLANDS 



3. Anamnia 



In the Clyclostomata, the lowest vertebrates in which adrenal 

 elements are certainly known to exist, our knowledge is con- 

 fined to the Petromyzonta and Bdellostoma. 



In Petromyzon [Giacomini] there are two distinct series of 

 bodies. One of these is represented by small, irregular, lobu- 

 lated structures in the wall of the posterior cardinal veins and 

 the renal arteries, and of arteries dorsal to the kidney. They 

 project into the lumen of the vessels, and consist of cylindrical 

 or polyhedral cells, containing granules which stain black with 

 osmic acid. These are the cortical or inter-renal bodies. The 

 other series, or the chromaphil series, extends from the region 

 of the second gill cleft to the tail of the animal. The bodies 

 of this series are thin strips of tissue running along the large 

 arteries and their branches. These bear the same relations to 

 the veins as the cortical bodies. 



This distribution of the chrome staining tissue in P. fluviatilis 

 has recently been confirmed by J. F. Gaskell. Extracts of the 

 regions in which this tissue lies, viz. , the walls of the aorta and 

 cardinal veins and the sinus region of the heart, cause a rise 

 of blood-pressure in the cat. 1 



In Bdellostoma the chromaphil cells have been observed, 

 but not the inter-renal or cortical. 



The relationships of the two adrenal representatives in 

 Elasmobranchs were first suggested by Balfour in 1878. He 

 called the representative of the cortex the " inter-renal," while 

 what we now know as the "chromaphil corpuscles" (repre- 

 senting the medulla of the adrenals of higher vertebrata) he 

 called " suprarenal bodies." That the paired " suprarenal 

 bodies " of Balfour really correspond to the medulla of the 

 mammalian organ was first definitely shown by the present 

 writer by the physiological test. This was fully confirmed by 

 the chemical test [Moore and Vincent] ; and that the " inter- 

 renal " of Balfour is really homologous with the cortex of the 

 mammalian body was rendered clear from the negative physio- 



1 The present writer, working in conjunction with Mr. W. E. Collinge, 

 made an attempt some years ago to find the adrenals in Cyclostomata, but 

 we considered that there was no satisfactory evidence to show that the 

 bodies described by Rathke, Miiller, and others had anything to do with the 

 adrenals. 



