WERNER MARCHAND 33 



by two, and the third and fourth by four envelopes. The accessory 

 parts of the organ have also been studied by Graber. 



At a moderate magnification it is possible to discern, in addition 

 to the tube extending backwards from the capsule, two other liga- 

 ments originating at the sides of the pear-shaped part, so that the 

 whole organ appears to be held in place by three ligaments, one of 

 which is the terminal tube. The two lateral ligaments extend ob- 

 liquely, crossing the two large tracheal trunks, in a forward and out- 

 wards direction, inserted in a place not determined by Graber but 

 probably lying in the seventh segment. At higher magnification the 

 anterior ligaments are found to be muscles, and immediately behind 

 the place of origin of these muscles two pairs of nerves are seen at- 

 tached to the capsule. The first nerve being rather thin forms imme- 

 diately at the head of the capsule a thick ganglion-like swelling, in 

 which several pale nuclei are discernible. The character of the end- 

 ing of this nerve has not been determined; Graber assumes that it 

 enters into connection with the capsular epithelium. Nothing more 

 is known about the termination of the second nerve which is much 

 thicker than the first one. 



All the parts described, the capsule, the tenninal tube, the muscles, 

 and nerves are connected with one another and with the surrounding 

 organs, as also with the tracheae and with the band-like extensions 

 of the heart muscles, by a peculiar connective tissue. The latter 

 shows the greatest affinity with certain elastic reticulate tissues of 

 higher animals. These tissues play a part, according to Graber, in 

 the extraordinary changes in the relative situation of the parts 

 during the movements of the larvae. Graber discusses the possible 

 function of the organ he described, assuming that it must be either a 

 gland or sense organ. The presence of a duct leading to the exte- 

 rior seems to indicate the former, but the arrangement of the con- 

 tents seems to contradict this view. 



If the organ is considered a gland, this would imply that a secretion 

 formed by the epithelial cells is discharged into the chitinous capsule. 

 In this case, however, no explanation is found for the presence of the 

 pedunculate bodies, not to mention the various interior secondary 

 capsules. The pedunculate bodies have no free opening, and while 

 they are hollow and possibly have been formed by invagination of 



