320 
nected with the muscles in the 8th and the 9th segment. Their 
only function is to open and shut the closing-apparatus. My trans- 
versal and horizontal sections are exactly in accordance with the 
statements of Raschke; the sections only show that two muscles, 
and not but one, are fixed to the rod. The horizontal sections 
present a Culex sipho with the two muscles fixed to the rod and 
further the two ventral muscles; the next section passes through 
the tracheæ, and a later cut would have struck the dorsal pairs 
of muscles. Fig. 32 z shows two slanting muscles running to the 
ventral flaps. 
Thus, in the Mansonia tube we find quite the same muscles 
as in the Culex tube. We find the same two long muscles (figs. 
33,341) fastened to the chitin rod. The dorsal and the ventral pairs 
of muscles are found even in the same position (figs. 33, 34æ and u). 
Only with regard to the above-mentioned long ligament found in 
the Mansonia I have been unable to find any correspondence with 
the Culeæ. : 
The muscle-apparatus of the Culex moves the flaps of the 
closing-apparatus; in Mansonia the corresponding muscles act in 
the same manner, but owing to the peculiar structure of the sipho 
this very action produces the piercing motion of that organ. In 
the case of Mansonia the modified closing-apparatus is not directly 
used in view of closing the spiracle; but, on the other hand, it 
may be supposed, that the spiracle is really closed, when the inner 
tube is pushed into the outer one. According to our interpretation 
of the tube of Mansonia as builded by the closing-apparatus of a 
Culex sipho, it is of interest to observe, as stated above, that the 
slender part of the Mansonia tube is fully destitute of muscles. 
This is just what should be expected if our supposition were Cor- 
rect. When regarding the sagittal section through the sipho of 
Mansonia we will observe, that the ventral muscle (fig. 33 7) 
which fastens at the point of origin of the cup, the point where 
the tracheal structure disappears, is connected with another, smaller 
muscle (fig. 334) in the 8th segment; this small muscle is further 
connected with the muscles in the Øth segment. This segment is 
traversed by a number of muscles beginning in the 8th segment 
and fixed to that system of chitin rods which support the dorsal 
and ventral part of the swimming-brush. As stated above, it will 
