WERNER MARCHAND 39 



they may be reduced to small fragments; the pedicel is inserted ob- 

 liquely, equal to the latter in length. The pedicel itself is chitinous 

 but not black; at most it is brown in the neighborhood of its inser- 

 tion in the globule; at the other end it has a widening by means of 

 which it fastens itself in a little cavity of the wall of the chitinous 

 capsule. The pairs of pedunculate bodies are attached each one 

 to the central portion of the anterior wall of the capsule itself, and the 

 pedicels are a little divergent so that the two spherical bodies are 

 located a certain distance from one another, suspended in the liquid 

 which fills the cavity of the capsule. The pedunculate bodies are of 

 dimensions increasing in the direction of the head; in a larva with 

 four pairs these bodies measured for each pair 11, 15, 16.5, and 18 jx 

 in diameter. 



Paoli explains the probable manner in which these cysts and the 

 tube are formed. It has been stated that the latter opens into the 

 innermost part of the sulcus which limits the eighth abdominal seg- 

 ment from the ninth; Graber did not see this opening but supposed 

 that it was to be found in the last — ninth — segment and certainly 

 independent of the alimentary canal and of the genital organs. 



The origin of this organ is thought to be a sac-like invagination of 

 the integument (Plate 10, Fig. 113). The most external part forming 

 the terminal tube, the more internal one a cystiform enlargement, 

 from the bottom of which the two pedunculate bodies originate, the 

 latter consequently being nothing but modified hairs derived from 

 the hypoderm surrounding the capsule. 



In this way it is evident that in the young larva which has not 

 yet undergone any molt there will be a primitive organ with only one 

 pair of pedunculate bodies. At each successive molt the chitinous 

 stratum of the organ remains in place, involved by a new stratum 

 formed around it by secretion from the hypoderm, and the old cap- 

 sule is pushed back distally. The new layer consequently forms a 

 new cyst with a transverse division separating two halves in the 

 anterior of which two new pedunculate bodies are formed, this being 

 the new organ, while the posterior half consists of. all that existed 

 before. In this manner, with the successive molts, an increase in the 

 number of the cysts and of the pedunculate bodies is brought about; 

 the capsule wall which is thinner when it belongs to a younger stage; 



