THE COASTS OF 8AINTONGE. 289 



peared perfectly colourless. These two liquids could 

 not therefore be of the same nature. If one were 

 the blood properly so called the other could be 

 nothing but the liquid of the general cavity. 



Such was the conclusion which I deduced from 

 observation alone, but which was fully confirmed 

 by experiment. On injecting the vessels, I filled all 

 the sacs without reaching the appendages, and I 

 found that, in order to penetrate into the latter, it 

 was necessary to pass the instrument into the lacuna?, 

 that is to say, into one of the dependencies of the 

 general cavity, and I then obtained the result of 

 which I have already spoken. Thus the lateral ap- 

 pendages of the Branchellion were not only branchiae 

 but they were moreover lymphatic branchias. 



In making this injection, the fluid did not enter the 

 appendages alone, for the coloured liquid reached 

 the intestine and presented on its surface a network 

 of large meshes. Besides this, it had filled a special 

 vessel placed on either side below the skin, and com- 

 municating with all the branchia3. Lacunary passages 

 connected these two cavities together, and the whole 

 of these canals, lacunas, and well-characterised ves- 

 sels, which were everywhere filled with a mixture of 

 chyle and lymph, represented, as we have seen, the 

 general cavity of the other Invertebrata. There 

 was only one portion of its dependencies consisting 

 of vessels properly so called which formed a true 

 rudimentary lymphatic apparatus. 



This was at once a totally novel fact in the history of 

 the Invertebrata, and a new proof that nature every- 

 where remains faithful to the great law of the pro- 



VOL. II. U 



