139 



between the first and second fingers (Nuttall and 

 SKipley). 



The labium proper stops short at the point of 

 junction of the labella, but is continued on its upper 

 surface as a blunt point covered with fine hairs 

 (Dutton). We may liken it to a pen continued on 

 beyond the penholder, the junction of pen and pen- 

 holder being the point at which the labella are hinged 

 on 



Dutton's Membrane.-^- -The area between the end 

 of the labium proper and the extreme tip is covered 

 by an extremely thin membrane (Dutton). In the 

 act of biting, when the labella are separated, this 

 membrane is somewhat stretched, and applied to the 

 skin. 



THE ESCAPE OF THE FILARIAL EMBRYO 



It has been shown by Low and James that the 

 filarial embryo occurred in the proboscis; according 

 to Low among the stylets. According to Dutton, 

 the embryo really lies in the tissue of the fleshy labium, 

 moreover with its head at the level of the membrane 

 described above, and that it is by the rupture of this 

 excessively thin membrane that the embryo escapes. 

 Grassi and Noe think that the embryo escapes through 

 the middle of the bent-up labium through a rupture 

 at this point, but Dutton's explanation seems more 

 likely. 



The epipharynx. Is the central tube through 

 which the blood is sucked. Its point slopes off somewhat 

 like the tip of a hypodermic needle. In cross section 

 it has the shape of an fl, the completion of the tube 

 being formed by the apposition below of the hypo- 



