40 VEGETABLE ORGANOGRAPHY. 



Section V. 



Of Strangulated Vessels. 



The Strangulated Vessels (PL 2, fig. 6,) have 

 been seen by Malpighi without his giving them much 

 attention. Mirbel was the first who really called the 

 attention of anatomists to the subject; and he has given 

 them the name under which they are here designated. 

 Treviranus described them under that of Corps 

 Vermiformes. They are tubes marked with dots in 

 transverse lines, as in Dotted Vessels, but contracted at 

 intervals by transverse strangulations, more or less per- 

 ceptible. Mirbel considers them as cellules, placed 

 end to end, which supposes that there exist diaphragms 

 which separate them : in following this opinion, it will 

 be necessary to class them among the modifications of 

 cellular tissue, and not among those of vascular tissue ; 

 but the existence of these diaphragms is very doubtful ; 

 the majority of anatomists deny it most positively. It 

 appears that from considering these bodies as a series of 

 cellules, Mirbel has been led to admit the existence of a 

 dotted cellular tissue; but their analogy with dotted 

 vessels is so strong, that it is impossible not to consider 

 them either as modifications of these organs, or as very 

 analogous organs. Kieser regards them as formed, like 

 the preceding, by spires or rings very distant from each 

 other, and connected by a dotted membrane. 



Strangulated vessels are abundant in roots, articula- 

 tions, joints, in branches and leaves at their first deve- 

 lopment, and, it is said, in natural or accidental warts. 



