Dr. Waller on the Origin of Mucus and Pus-globules. 399 



The capillaries became rapidly distended with blood, and the 

 colour of the entire organ was darker from this injection. 

 After exposure to the air for two or three hours it was again 

 examined : the appearance presented by its inferior surface is 

 represented in Plate II. fig. 1. The capillaries were so forcibly 

 distended that they attained double their ordinary calibre, and 

 by their numerous swellings and contractions resembled a knot- 

 ted stick. The blood was generally stagnant, and the outlines 

 of the separate particles could not be distinguished : the cor- 

 puscles could only be known from the discs by their white- 

 ness. Over the whole surface of the tongue were numerous 

 corpuscles outside of the vessels, and occasionally a few scat- 

 tered discs. The extravasated blood-discs were rapidly altered: 

 they appeared to lose their redness, and to become broken 

 up into granules which soon disappeared. The corpuscles 

 appeared to retain their form much longer. The engorged 

 vessels became rapidly very irregular in their calibre, by the 

 formation of numerous indentations or concavities throughout 

 their length. Opposite these concavities were found one or 

 more corpuscles which had escaped. The upper surface of 

 the vessel likewise presented numerous dark spots of an irre- 

 gular shape with very distinct dark edges. These were evi- 

 dently small depressions or foramina seen in full, while the 

 former were viewed in profile. In some instances, the manner 

 in which the corpuscle escaped from the interior of the tube 

 could be distinctly followed : that part of the tube in contact 

 with the external side of the corpuscle gradually disappeared, 

 and at nearly the same time might be seen the formation of a 

 distinct line of demarcation between the inner segment of the 

 corpuscle and the fluid parts of the blood in contact with it. 

 Any slight agitation then was capable of disengaging the cor- 

 puscle from the vessel to which it was now external, and in its 

 place a concave depression remained, which appeared suffi- 

 ciently protected by some membrane, as to oppose effectually 

 the exit of the discs and the fluid parts of the blood. In rare 

 instances the blood-discs and corpuscles might be seen sepa- 

 rate and distinct within the tube, while occasionally some of 

 the latter were seen to escape through the sides; the contents 

 of the tube oscillating synchronously with the increased action 

 of the blood in the surrounding vessels. In general, it is ob- 

 served that the corpuscles escape more frequently at a bend 

 or angle where there is a subdivision of the tube : those in the 

 interior are also observed to collect there in greater numbers. 

 In some places, the indentures formed by the extravasated 

 corpuscles were so deep that the vessel appeared to be quite 

 disconnected ; and such was sometimes really the case ; but 



