Zur Aetioiogie der Wipfelkranikheit der Noiine. 19 



The kernel-substance answers (as in the čase of jplants) 

 "to the irritations caused by the toxine secreted from the 

 virus with the trans for mation of the kernel-substanee, and 

 produces a homogeneous substance — the polyhedral body — 

 which envelopes the noxious microorganisms. 



14. This »gall« has in the nun-moth the form of the 

 tetraeder, in the silk-worm that of the dodekaeder, in the 

 Sphingid-moth that of the hexaeder. Every species has its 

 spéci fic form. 



15. The polyhedral body insulates the virus. If then the 

 whole kernel-protoplasma was exhausted in producing of the 

 polyhedral b. (i. e. for the defence of the sick cells) the 

 nucleus must degenerate and the cell dies. 



The Caterpillar remains healthy if it is possible to made 

 Ihc attacking virus innocuous by producing only a little 

 number of polyhedral b. The diseas afterwards begins to be 

 chronic. 



16. The whole cycle of the wilt is as follows: 



The polyhedral body reaches per os the intestine The 

 virus liberated by the intestin-solution from the polyhedral 

 bodies penetrates through the gut-wall into the blood and 

 arrives with the blood in quiet places, for in., skin or fatt- 

 body lacunoms. From here the Chlamydozoa penetrate into 

 the nuclei and begin to multiply. 



At first the hypodermis-cells swell up and their nuclei 

 are densely packed with polyhedral bodies. Now the fatt- 

 body and the peritracheal membráně wille be attacked. Now 

 we can find the first polyhedral b. phagocytized in the 

 blood- cells. 



They orginate from the burst hypodermis-cells. ^ 

 Then follows the muscular systém. The body begin to 

 be weak and at last the affection of the nervous systém 

 causes a generál lameness and the body hangs down fixed 

 only by one or two legs. 



17. The course of the wilt in the single cell is well ex- 

 plained in the adjoined Fig. 7, PÍ. I, in which all the succe- 

 sive changes of the nucleus are marked (Types A, B, C, D, E, F). 



