W. H. FURLONGE ON THE PULEX IRRITANS. 15 



possessed in so remarkable a degree, maintained that in the case of 

 the flea a gizzard ovglit to be found, as, in his opinion, some such 

 apparatus would be requisite for the purpose of breaking down the 

 blood discs and preparing them for assimilation. It was not until 

 some time after the death of Mr. Quekett that the actual exist- 

 ence of the organ he had predicated was demonstrated, the flea's 

 gizzard having been dissected out and isolated for the first time, I 

 believe, by Bourgoyne, of Paris. We must regret that the Pro- 

 fessor did not live to see the truth of his conjecture thus con- 

 firmed. 



More skilful fingers than my own have enabled me to figure the 

 accompanying drawing (Fig. 2), which has been taken from a pre- 

 paration by Mr. Topping. With admirable skill this minute portion 

 of the insect's structure has been isolated, and laid out upon the 

 glass slide. It will be seen to possess the well-defined and powerful 

 muscular structure common to the gizzards of insects, though the 

 teeth or rasping appendages usually found in such insects as feed 

 upon hard food are wanting. In the flea's gizzard, however, such 

 aids would have been clearly unnecessary, the breaking down of the 

 blood corpuscules being, as is easily conceived, rapidly and perfectly 

 accomplished by the passage of the food between the rubbing sur- 

 faces of the organ when actuated by its powerful muscular bands. 



The Second Stomach, or Intestinal Sac. — The blood constituting 

 the animal's food having been thus triturated, passes on through a 

 comparatively short and straight gut or intestinal canal, which is 

 furnished at its junction with the posterior extremity of the stomach 

 with a powerful sphincter muscular valve, controlling the passage 

 of the food, into the digestive sac or second stomach, as it may be 

 termed. In most specimens of the insect that I have examined, the 

 capacity of this sac seems to be almost, if not quite, as large as that 

 of the first stomach. The second stomach, like the first, is sub- 

 jected to constant dilations and contractions, but these do not occur 

 in waves or undulations ; in fact, the sac being sub-globular inform, 

 and not elongated, like the first stomach, its contractions 'are 

 necessarily accomplished in a different manner. Moreover, the walls 

 of the sac are not themselves muscular, and therefore its movements 

 are not produced by the contractions and dilations of the parietes 

 themselves, but by the agency of muscular bands attached to them, 

 which are set in action at different times, and seem to pull the walls 

 of the sac together, from side to side, by which movements the fluid 



