286 Dr. Waller on some Tissues of the Animal Frame. 



cles from the capillaries. In a future communication I pur- 

 pose to enter fully into this subject, but at present I will con- 

 fine myself to the establishment of this fact by the two follow, 

 ing observations extracted from my notes. 



August 1st. — A toad was examined after it had been dead 

 two or three hours ; the abdominal cavity and cellular tissue 

 were found distended by a limpid dropsical collection of serum, 

 containing numerous white corpuscles, with a few blood-discs. 

 The mesentery was arranged for microscopic inspection, and 

 its capillaries were found filled with corpuscles and discs all 

 at rest. Upon examining the membrane I observed corpus- 

 cles within the vessel, which disappeared from the spots where 

 they had previously been detected, and after a few minutes 

 were no longer to be found. The only traces of their former 

 situation were curved indentations in the vessel, of the same 

 size as the corpuscles, and a solution in the continuity of the 

 parietes of the vessel at those points. At other parts, where 

 several of the corpuscles had existed together, the capillary 

 tube seemed completely interrupted, as if it had been en- 

 tirely dissolved. While the corpuscles were disappearing 

 in this manner from the vessel the red discs remained station- 

 ary. 



August 29th. — The tongue of the live frog was distended in 

 the ordinary way. After the observation had continued for 

 half an hour, numerous corpuscles were seen outside the ves- 

 sels, together with a very few blood-discs, in the proportion 

 of about one to ten of the former. The extravasated parti- 

 cles were equally diffused over most part of the tongue. No 

 appearance of rupture could be seen in any of the vessels. 

 The corpuscles were generally distant about mra, 03 from their 

 parietes. After the experiment had lasted about two hours, 

 thousands of these corpuscles were seen scattered over the 

 membrane, with scarcely any blood-discs. The process by 

 which they passed out of the vessel could be best observed in 

 a capillary containing stationary blood particles. Generally, 

 at a slight distance from it, some extravasated corpuscles could 

 be detected, and at the nearest opposite point of the tube a 

 small concave depression was presented. Frequently, near 

 this depi'ession, numerous corpuscles were collected within 

 the tube, as if about to follow the rest which had escaped. 

 These were frequently agitated by a movement of oscillation, 

 which showed that there was no open point in the tube. In 

 other spots some of these corpuscles were seen protruding half 

 out of the vessel. Whenever the current re-occurred in a 

 vessel presenting these appearances, the depressions and un- 

 evenness quickly disappeared, and no trace of the corpuscular 



