272 RAMBLES OF A NATURALIST. 



as in all the Annelids, properly so called, there is no 

 heart ; whilst the vessels, which are everywhere of 

 equal calibre, do not give origin to any secondary 

 branches. In respect to the circulation, the lower 

 Articulata present a much greater similarity to the 

 Vertebrata than to Insects or the higher Molluscs, 

 whose organisation is nevertheless very far superior 

 to their own.* 



Even the Yertebrata obey the common law, and 

 in the lower representatives of this type in the 

 fishes we still meet with examples of this lacunary 

 circulation. This important fact, which could not 

 have been anticipated a few years ago, was discovered 

 at Paris simultaneously, although independently, by 

 two anatomists, MM. Natalis Guillot f and Robin, 



* This is a very important result, which moreover derives con- 

 firmation from the comparative study of several other groups. We 

 still meet with some naturalists, who, guided solely by their pre- 

 conceived ideas, wish to insist that there must be not only necessary 

 physiological relations between each functional apparatus, but they 

 would make it appear that there is an anatomical dependence among 

 them, which is regulated by laws, which exist only in their own 

 imagination. In the eyes of these naturalists, no apparatus can be 

 simplified or degraded without inducing a corresponding simplifica- 

 tion and degradation in all the others. In refutation of such views, 

 it is sufficient to refer those who uphold them to the study of the 

 circulation in Insects and in Annelids. 



f M. Natalis Guillot, who is physician to several of the Paris 

 hospitals, affords a happy illustration of the manner in which 

 scientific pursuits can be combined with the practice of a laborious 

 profession. His Exposition Anatomique de I' 'Organisation des 

 Centres Nerveux, which gained for him the prize offered by the 

 Brussels Academy of Sciences, will ever remain one of the most 

 trustworthy works on this difficult subject. M. Guillot has pub- 

 lished numerous memoirs illustrative of various other points in 

 comparative anatomy and physiology. 



