176 THE DUCTLESS GLANDS 



by many workers as a regular phenomenon. It is found that 

 the splanchnic arteries are constricted while the peripheral 

 are dilated with very small doses. But with such doses the 

 dilation of the peripheral vessels begins earlier and lasts longer 

 than the constriction of the splanchnic. The result is that the 

 splanchnic rise is masked by the peripheral fall (Hartman). 



It has been mentioned above that the " paired suprarenal 

 bodies " of Elasmobranch fishes yield an extract which pro- 

 duces the same physiological effects as adrenal medulla. In 

 1898 Langlois showed that the adrenals of the frog (which 

 contain masses of chromaphil cells) contain an analogous sub- 

 stance and are functionally homologous with the glands of 

 higher vertebrates. Biedl and Wiesel proved that the ' ' Neben- 

 organe " of Zuckerkandl contain the active substance. The 

 present writer has further shown that the " abdominal chroma- 

 phil body " of the dog also contains the pressor substance, 

 and Fulk and Macleod that the retroperitoneal tissue of various 

 animals contains substances having the same effect on intes- 

 tinal and uterine muscle as adrenin. Mulon has raised the 

 blood-pressure of an animal by injection into the circulation 

 of an extract made from the carotid body of the horse (which 

 body was shown by Stilling to contain chromaphil cells). It 

 seems clear, therefore, that all chromaphil tissues, whether 

 contained in the adrenal or not, yield adrenin, or a substance 

 having similar chemical and pharmacodynamical properties. 1 

 How far this conclusion may be adduced, in conjunction with 

 other observations, as evidence of an internal secretion on the 

 part of all these tissues, is a matter for subsequent considera- 

 tion (see p. 237). 



A pathological effect which has been noted by Josue as a 

 result of repeated injections of adrenin into the auricular vein 

 of the rabbit is a degenerated condition of the wall of the larger 

 arteries, especially of the aorta (arterio-sclerosis). Atheroma, 

 calcification, and even aneurisms are also described, and the 

 changes have been recorded in the pulmonary and other 

 arteries. It is said that these effects are not peculiar to 

 adrenin, but are produced by other blood-pressure raising 



1 Of course, this conclusion is based upon the provisional assumption that 

 " chromaphil " tissues are specific in their nature, and are everywhere of the 

 same essential character. It is not out of the question, however, that there 

 may be some cells which stain brown with bichromate, which are, nevertheless, 

 of a different character. 



