THE COASTS OF SICILY. 215 



if, in the Ccase of man, the hand, mouth, stomach, 

 intestine, and lungs, indefinitely multiplied, were 

 attached to as many threads, issuing from an isolated 

 vertebral column. All these organs intermix and 

 become incessantly blended together round the 

 slender axis which connects them. The organs of 

 locomotion are alone grouped into one mass, apart 

 from the rest, at the anterior extremity. They 

 consist of a considerable number of small bells sol- 

 dered together to the central stem, with the opening 

 directed backwards. These little bells are all inces- 

 santly dilating and contracting. By these alternate 

 movements the water contained within their cavities 

 is forcibly driven out, and the little bells being |)ushed 

 forward by the resistance of the liquid, draw after 

 them the other parts of the body. This peculiar 

 structure, which has no analogue in the animal king- 

 dom, places the Stephanomia3 apart from all other 

 animals ; hence it is only by a careful study of their 

 embryology, that we can hope, by the discovery of 

 their real affinities with other types, to ascertain 

 their correct place in our zoological system. 



Of the three naturalists of our expedition, I was 



from which to consider the structure of these singular beings. 

 According to them each of the Siphonophora is a colony of distinct, 

 but incomplete individuals, some of which are charged with the 

 functions of locomotion, others with those of nutrition, &c. Al- 

 though this method of considering these organisms may at first 

 surprise us, we must admit that recent facts have come to light in 

 reference to the lower animals, which seem to give it a certain 

 character of probability. At all events, new researches would 

 appear necessary to decide this question, which perhaps can only 

 be completely solved by the study of their embryology. 



P 4 



