388 METAMOKPHOSIS OF FILARIA SANGUINIS HOMINIS IN MOSQUITO. 



apparently brisker at the end of this time than at the beginning ; it was only suspended when 

 the cover-glass was removed, and the slide dried. 



Figs. 34, 35. Show with tig. 24 the process of withdrawal of the body from the tail. 



Fig. 36. Probably a dead Filaria with irregular bulgings, vacuoles, and signs of degeneration. 



Fig. 37. Head of fig. 29 more highly magnified, and drawn at a slightly later hour, when the body on 

 dying had somewhat retreated from the integument. 



Figs. 38 & 39. From the same mosquito, showing differences in the rate of progression of meta- 

 morphosis. 



Figs. 40, 41 & 42. Also all from the same insect. 



Fig. 43. Caudal papillae developing. 



Fig. 44. Pharyngeal lines very distinct, from a Filaria in the fifth stage. 



Fig. 45. Showing a sort of horny thickening of the tips of the lips at the fourth and early fifth stages. 



Fig. 46. The sickle-shaped integumental caudal appendage not yet shed; caudal papilla? developing, 

 and possessing a delicate skin separating them from the original integument of the earlier 



