— 35 — 



devoured, so that when the case is opened only the most résistant 

 chitinous remains of the host larva are found amassed in the 

 posterior end of the case cutside the cccoon which the parasite 

 now has made and which fills up the rest of the case. In the 

 anterior end of the cococn, there is an open fissure between the 

 side wall and the end wall, and inside this fissure the mentioned 

 band is superficially attached or stuck to the wall, from which 

 it can easily be removed. Outside the fissure the band péné- 

 trâtes the silk netting (made by the host) and will show a length 

 of until 26 mm (in Silo pallipes which is the common hos*: in 

 North Sealand certainly hardly more than 14 mm), its breadth 

 is 1 mm. 



As the band pénétrâtes the cocoon and is fastened inside this, 

 and as the cocoon's originating from the parasite is beyond ail 

 doubt, it is évident that the band is formed by this latter, and 

 not by the host, as SlEBOLD (1) believed. And when we see the 

 protruding hypopharynx and the enormously developed salivary 

 glands there can be no doubt that the band is formed by sécré- 

 tion from the salivary glands. As the gut is clcsed posteriorly 

 no other origine can be proposed. When examining a host case 

 having a band still growing I always found that the larva lay 

 with its head directed the same way as the band. When exa- 

 mining a case having a fully developed band I hâve in some 

 instances found the parasite to be orientated with anal end 

 against band end of the case, this larva thus — after having 

 finished forming the band — must hâve turned round in the case 

 in spite of the greatly limited room, on account of its very great 

 capability of changing its shape this may be imagined to take 

 place in the same way as fly larvae do (turning round a little 

 of the head end, pumping blood into this part, turning some 

 more segments, pumping blood in thèse, a.s.f.). The great 

 capability of changing its form surely is of importance in as 

 much as the larval body thus can thrust against the sides of the 

 case when the growing band is to be pushed outwards, and in 

 t!his act of pressing against the wall the chitinous warts also 

 play their part. Of course the band will grow longer in its 

 proximal end (into the cocoon) which will also always be of a 

 much more whitish and soft ccnsistence than the free part, and 



(1) Stett. Ent. Zeîig., XXII, 1861, p. 59. 



