ON INJECTING THE LYMPHATIC SYSTEM OF REPTILES. 163 



fluid coloured red or white, without doubt the fact of which we speak 

 would not have escaped the notice of this anatomist. 



In my researches on the common salamander, I will prove to you in 

 the most manifest and positive manner, that Panizza is mistaken with 

 regard to the lymphatic vessels of this reptile, and that he has fallen 

 into error respecting the inferior or abdominal vena cava, of which he 

 has misunderstood the direction and ramifications. I will further prove 

 in the most incontestible manner, with the aid of drawings, made from 

 nature, and placed side by side with his, that all the plates annexed to 

 his work though drawn and engraved by a most talented artist, repre- 

 sent the lymphatic vessels entirely deformed, and that their deformity 

 arises from Panizza having made use of mercury in his injections for 

 demonstrating the lymphatic vessels. 

 Pavia, Nov. 1 6th, 1841. 



Note on the above by M. G. Breschet. 



WITH this letter M. Rusconi forwarded two sketches, the description of 

 which will be hereafter given, and several small dried anatomical prepa- 

 rations, made from reptiles of which he had injected the arteries and 

 lymphatic vessels. These two orders of vessels can be distinctly ob- 

 served ; but the state of desiccation in which they were did not allow 

 of their examination with sufficient surety and precision, to determine 

 with exactness the relations of these vessels with each other. This 

 examination can only be made in a rigorous manner upon fresh portions 

 injected in the best possible manner, or on portions preserved in a liquid 

 and equally well injected. 



We have, with M. Rusconi, altogether abandoned the injection of 

 lymphatics with tubes and mercury, on account of this metal rupturing 

 frequently by its weight, the vessels and lymphatic reservoirs, the walls 

 of which are very thin. This method is above all insufficient and even 

 bad, when investigations are entered upon and the course and ramifica- 

 tions of the vessels not hitherto known. If one of the small canals be 

 opened, the metal runs out, and it is not further possible to continue 

 the researches. 



I believe, with M. Rusconi, that the expansions (bosselures) or nodo- 

 sities which the lymphatics possess at various parts, are principally due 

 to the presence and to the weight of the mercury. In my injections 

 with other substances besides the fluid mercury, the vessels are more 

 regular in their outline and much resemble those of arteries ; whilst, it 



