Johannes Fibiger and Hjalmar Ditlevsen: Spiroptera neoplastica n. sp. 



As will be seen from the table it did not cause any difficulty to produce deposita of ne- 

 matodes in the muscles of the cockroaches. In no respects did these worms differ from the 

 nematode found in P. americana and also here they were coiled up trichina-like in spirals, 

 often surrounded by a fine capsule. On feeding rats on cockroaches (P. orientalis) infected in 

 this way the nematode was f urther transmitced to rats, as seen from the following table which 

 gives a view of the first experiments of this sort. 



Number 

 of rats 



Each rat 

 fed on cock- 

 roaches (P. 



orientalis) 



i Nematodes 



found in 



' the stomach 



of rats 



Nematodes 

 and patholo- 

 gical changes 



New-growth 



found in the found in rats 

 stomach 1 

 of rats I 



6 

 6 

 2 

 8 

 16 



Number of P. or. Nnmber of rats: Number of rats: Number of rats: 



Total: 



38 



2»/2-5 



12 



1—3 



15—103 



2 

 1 

 O 

 3 

 16 



22 



1 

 O 

 O 

 1 

 13 



15 



Control experiments: Rats fed on non-infected cockroaches (P. orientalis) 



43 



11—50 



O 



O 



O 



Thus by feeding rats on cockroaches (P. orientalis) infected with fæces, (/) or eggs of the 

 nematode, (e) the worm was transmitted into 22 out of 38 rats, while in 43 rats used as 

 Control animals and fed on non-infected cockroaches from the same locaUty, the nematode was 

 not found at all. 



After this the transmission of the nematode by P. orientalis does not cause any difficulty 

 and for more than a year in a long series of experiments, has now*) been carried out quite 

 regularly at the Institute. When for the feeding experiments is used a not too small amount 

 of cockroaches, infected during a longer period by rat's excrements containing eggs, the infection 

 of the rats will as a rule turn out successful. Out of the 16 rats noted above, fed each of 

 them on 15 — 103 cockroaches, the nematode was observed in all of them without exception; in 

 13 rats anatomicai changes were found simultaneously, and in 7 cases the changes were 

 tumour growths of the same type as those originally observed. 



The Ufe-cycle of the nematode now, according to the observations already pubhshed and 

 here only sketched, must be as follows: The nematode Uves in the pavement epithelium of 

 the stomach and of the oesophagus of the rat — occasionally also in the epithelium of the 

 tongue and mouth. It here reaches sexual maturity and evacuates ripe eggs, containing 

 embryos, which are liberated by desquamation of the epithelium and passed with the excre- 

 ments. 



') December 1913. 



