NEW MAI.f.Ul'HAGA. 205 



chitiiious rod reaching to the third abdominal segment, 

 and that within this tube is still another which con- 

 tinues anteriorly into a whi[»-lash beset with numerous 

 spines or bristles. It is rather hard to. imagine how 

 structures such as these could exist in the manner 

 described; and dissected specimens, entire specimens 

 cleared with Kau dt fAiba.rru(jue and stained, and 

 sections cut in longitudinal and transverse directions, 

 indicate that Grosse's description is not entirely cor- 

 rect. The structure of the various parts which Grosse 

 has mentioned is apparently as described in the follow- 

 ing account. 



When the abdomen of tiu' male is opened from above 

 there is to be seen in it, lying along tlie middle line and 

 ventral to the alimentary canal, a large, compact mass 

 of muscles reaching from the last segment into the 

 fourth. The posterior three-fourths of this mass is 

 composed of transverse fibers, and the anterior one- 

 fourth of longitudinal fibers which converge to a point 

 in the fourth segment. This structure forms the most 

 prominent organ in the abdomen and is easily taken 

 entire from the bodv bv detachiny; it from the bodv- 

 wall at the posterior en<l. Under a low-power lens it 

 can easily be seen that the transverse muscles of the 

 posterior three-fourths are much curved, but are a little 

 less than semicircular. Tluir dorsal ends are attached 

 to a vertical sheet of meml)rane whicii extends down 

 between them from above as a fold from a thin mem- 

 brane surrounding the whole mass. Their lower ends 

 are attached to a thin, transverse, ventral plate. By 

 dissecting the libers apart it is found that they, together 

 with the ventral ]^late to which their lower ends are 

 attached, surround a cylindrical cavity. Within this is 

 a thin-walled. menil)ranous tube ojicu in front. This 



