Johannes Fibiger and Hjalmar Ditlevsen: Spiroptera neoplastica n. sp. 9 



ficially infected cockroaches (P. orientalis) 7 rats presented tumour growths, 6 definite hyper- 

 trophy of tlie epithelium, while 3 rats did not show any pathological changes — besides ne- 

 matodes. 



In the slightly definite cases (16 rats) the cardiac portion of the stomach. was only changed 

 very moderately, tlie hypertrophy of the mueous membrane being either circumscribed or diffuse. 

 Corresponding to this, the microscopical examination showed a proliferation of the squamous- 

 celled epithelium of the mueous membrane, combined with a definite hypertrophy and desqua- 

 mation of the stratum corneum. As a rule, the mueous membrane and submucosa contained 

 slight inflammatory processes consisting mainly in colonies of leucocytes, lymphocytes and 

 plasma-cells. 



In cases where the pathological changes must be characterized as definite (29 rats) the 

 condition of the mueous membrane was diffusely hypertrophic, irregularly folded and wrinkled, 

 often beset with small papillomatous prominences. In microscopical examination the mueous 

 membrane, and the connective tissue of submucosa appeared to be proliferated, the latter 

 forming the stock of small papillomes which protruded on the surface of the mueous membrane 

 and were covered with hyperplastic epithelium; in some cases the inflammation had even 

 reached the muscularis and the serosa. 



The proliferation of the epithelium was very definite, not only was the stratum corneum 

 hypertrophically changed but the lower coats as well; and often long tongues of epithehum 

 were seen going deep down, displacing, and even perforating the muscularis mucosæ, so that 

 submucosa contained spurs of epithelial islets. 



In cases where the pathological changes showed themselves as violent or as tumour growths 

 (23 rats in all) the stomach was very much enlarged, the wall of the cardiac portion very 

 thick, and the mueous membrane set with petiolate irregularly branched papillomes or wall- 

 like prominences, which in all cases made the ventral wall measure nearly 1 — 1^3 mm. in 

 sections; in several cases the cavity of the fundus was absolutely diminished by the papil- 

 lomes, which in other cases not only caused an obliteration of the cavity but even pro- 

 truded into the pyloric portion. The outside of the stomach was irregularly rugged, with 

 globular or flat prominences; in some cases even petiolate protuberances were observed. 



Microscopical examination showed that these changes were due to a further development 

 of the tumours already described. 



The connective tissue of the submucosa appeared to be a seat of violent inflammatory 

 processes and new growth, so that branched coral- or crater-shaped prominences of connective 

 tissue covered with coats of hyperplastic epithelium, projected into the stomach as enormous 

 papillomes, 1 — IV2 cm. high. 



By cooperation of these various processes: 



Proliferation of the heterotopic epithehum, and inflammation and new growth of the 

 connective tissue of submucosa, enormous pathological changes were produced. In faet, the 

 prohferation of the heterotopic epithehum in several cases destroyed the papillomatous wall 

 of the fundus to such an extent that it consisted of nothing but great masses of epithelium 

 covered with a thin serosa. In such cases the bundles of muscularis were atrophic, dismembered 

 or quite destroyed. In all cases a definite eosinophily was observed in mucosa and submucosa 

 of the ventral wall. 



Moreover, it must be pointed out that in 5 laboratory rats fed on cockroaches (in 4 cases 



