APPENDIX. 345 



Note XHI. 



Van Beneden, who is professor at the University of 

 Louvain, is one of the most active and distinguishhed of 

 our modern zoologists. He has published numerous works 

 and memoirs on almost all the important groups belong- 

 ing to the sub-kingdom of the Invertebrata. Amongst his 

 various publications, I may instance his Exercises Ana- 

 tomiques, which principally refer to the Molluscs, and his 

 Recherches sur les Bryozoaires d'eau douce et d^eau salee. 

 For the last few years, M. Van Beneden has devoted 

 himself specially to the study of intestinal worms, and 

 he has already published the results of a series of very 

 important researches, which gained for him the prize 

 offered by the Academy of Sciences of Paris in 1853. 



I regret that I cannot here give a circumstantial 

 account of this splendid work, in which the author has 

 considered, from every point of view, the difficult and 

 complex subject of the development of these animals. 

 This work, which will be printed at the expense of the 

 Academy, is still unpublished ; but those persons who 

 take an interest in the question may form a general 

 idea of the results obtained by the author, by consulting 

 the analysis which I drew up, in my capacity as re- 

 porter to the Commission appointed to award the prize. 

 I will here merely observe that this work, together with 

 the less extended researches of Dr. Kiichenmeister, have 

 shown, with almost unquestionable certainty, that a 

 large number of the intestinal worms are produced by 

 processes analogous to those which we meet with in 

 many other animals, as, for instance, in the Acalephee ; 

 and that, before they attain their perfect state, they must 

 pass through different conditions, corresponding in some 

 degree to those which I have described in reference 

 to the Medusae. It is, however, farther shown that 



