1912.] Manganese Content of Transplanted Tumours. 



179 



quantities of the blood of several mammals and birds. It serves also as a 

 control to the purity of the reagents used. The analytical results in the 

 several tumour strains examined are shown in the adjoining table. 



Summary and Conclusions. 



As a general conclusion it may be stated that the quantities of manganese 

 found in transplanted mouse and rat tumours, whether carcinomata or 

 sarcomata, and also in the so-called lymphosarcoma of the dog, are very small 

 — they vary between - 004 and 0'012 mgrm. per 100 grm. of the fresh 

 material. 



In order to obtain an idea of the comparative amounts of manganese con- 

 tained in the normal mammary gland and the epithelial tumours derived 

 from it, two manganese estimations were made of normal mouse mamma. In 

 the first, 15 grm. of lactating mamma were analysed. Only - 004 mgrm. was 

 found, i.e. - 026 mgrm. manganese per 100 grm. For the second determina- 

 tion, 14 grm. of resting mamma were incinerated. The amount of manganese 

 present was - 002, i.e. 0'014 mgrm. per 100 grm. Though the comparison be 

 not strictly exact, nevertheless the figures obtained allow this general 

 conclusion to be drawn, that the epithelial transplantable mouse tumours 

 developing in the mammary gland do not contain a larger amount of 

 manganese than their normal mother tissue. 



Furthermore, there are not very marked differences in the percentage 

 distribution of manganese between carcinomata and sarcomata. In connec- 

 tion with this observation it may be also mentioned that the carcinoma and 

 sarcoma strains of the mouse tumour "100" do not exhibit appreciable 

 differences in their manganese content. 



