OF HYDATIDS* 265 



But other authors have affirmed, that they had 

 injected the vessels proper to the hydatid. Dr. 

 WALTHERUS,of Berlin, supposed, that he had filled 

 the blood vessels on the outer coat of an hydatid, 

 which was contained within the liver ; but it is not 

 improbable, that he had mistaken the vessels on the 

 peritonaeum of the liver for those of the hydatid. 

 Watery vesicles, or dropsical cysts, as they have 

 been named by some authors, are very different from 

 hydatids ; for in these we observe only a single thin 

 coat, firmly attached to the neighbouring parts, on 

 which several blood vessels, filled by red blood, 

 may be observed. Such cysts frequently adhere to 

 the extremities of the fallopian tubes, to tlie liga- 

 ments of the uterus, to the choroid plexus, to the pla- 

 centa, kidneys, or are sometimes lodged within the 

 glandular viscera, and are also sometimes imbed- 

 ded in the mammae and testicle. I have seen them 

 filled by a fluid of the colour of the ink of the cuttle 

 fish, when these organs have been reduced to a scir- 

 rhous state. Though tlie arteries proper to the 

 coats of hydatids be very small, yet the watery liq- 

 uor whicli fills the hydatid, is secreted by them, and 

 in some cases even bone. 



The hydatid is probably nourished by absorp- 

 tion, and not by continuous vessels from its cyst, 

 and may be compared in structure to the echinus es- 

 culentus of Linnaeus ; tbat is, absorbent vessels 

 take up its nourishment from the containing cyst ; 

 and in like manner, the small hydatids, contained 



within a larger hydatid, after being separated from 

 34? 



