On Flukes. 29 



Italian naturalist Nardo. This is the longest fluke-worm 

 known ; it attains a length of no less than five inches, and has 

 hitherto been found only within the stomach of a large fish 

 {Luvarus imperialis), which frequents the Adriatic Gulf and 

 the coasts of Sicily. 



The ordinary aspect of these creatures is not such as would, 

 at first sight, recommend itself to the attention of the general 

 observer ; yet those who will take the trouble to submit them 

 to microscopic examination will find their senses gratified, not 

 only by the evidence of a fair exterior, but by the exhibition of 

 elegantly-grouped internal organs. If, further, a satisfactory 

 attempt be made to inject some of the larger species, the 

 beauty of the specimens will be thereby increased tenfold. 

 To be completely successful, however, finely-pointed syringes 

 must be employed, aided by the most careful and delicate 

 manipulations. Up to the present time, indeed, we believe 

 that the so-called vascular system of the trematoda has been 

 efficiently injected only by M. Emile Blanchard, of Paris, and 

 by the author of this communication. 



The introduction of pigments not only renders the objects 

 more attractive in appearance, but, at the same time, facilitates 

 our comprehension of their anatomical peculiarities. In the 

 illustrations, therefore, here or in future selected, to render 

 this subject clear, we shall employ colouring as follows : — 



Blue for the digestive system. Hitherto we have found 

 artificially prepared ultramarine to answer the purpose admi- 

 rably. Specimens of flukes from the giraffe, thus injected by 

 the writer, may be seen in the Anatomical Museum of the 

 University of Edinburgh, and in the author's private collection 

 of Entozoa. 



Bed for the water-vascular system. The distinguished dis- 

 ciple of Baron Georges Cuvier, above-mentioned, has here 

 employed vermilion, and we have adopted the same plan. 

 The principal figures in the accompanying plates will be, in 

 part, taken from the inimitable drawings of Blanchard, as given 

 by him in Victor Masson's imperial-octavo edition of "he 

 Regne Animal," and in the eighth volume of the Zoological 

 division of the third series of the "Annales des Sciences Natu- 

 relles." From the extreme beauty of the representations just 

 referred to, some parasitologists have been led to question their 

 accuracy. Recently, however, the writer had the satisfaction 

 of convincing an eminent German naturalist that his surmises 

 in this respect were fallacious ; for, on exhibiting to him two 

 similarly injected flukes from the author's own collection, he 

 credited the French helminthologist with the highest manual 

 skill, to which we believe him to be justly entitled. 



Yellow for the reproductive system. This colour is usually 



