The influences of the extracted solution of the guinea pig spleen were observed on the process of pyridin-verdohaemichromogen or globin-verdohaemichromogen formation, after the extracted solution of the guinea pig liver with physiologic saline (abbr. the extracted solution) was added to pyridin-haematin or haemoglobin and adjusted to the pH 8 with soerensen M/15 phosphate buffer solution and then installated at 33℃. The results were as follows. 1. Trace of globin-verdohaemichromogen was spectrophotometrically proved from the extracted solution of spleen after 24 hours, but the increasion of pyridinverdohaemichromogen or globin-verdohaemichromogen was not observed on the addition of pyridin-haematin solution of haemoglobin solution into it. 2. The formatin of pyridin-verdohaemichromogen from pyridin-haematin was more effective on the use of the mixed solution of the liver extract and physiologic saline in same dosis than it was on the use of the mixed solution of the spleen and liver reextracts. 3. As the extracted solution of spleen was used first on the preparation of pyridin-verdohaemichromohen from pyridin-haematin, the globin-verdohaemichromogeh formation with the extracted solution of liver was inferior to the use of the above reextraoted mixture, but it was more promoted hourly on this occasion than on the use of the mixed solution of the foregoing hours, and the maximum value was also same. 4. The formation of globin-verdohaemichromogen from haemoglobin was more effective on the use of the mixed solution of the liver extract and physiologic saline in same dosis. This was opposite to the occasion of pyridin-haematin. 5. As the extracted solution of spleen was used first on the preparation of globin-verdohaemichromogen from haemoglobin, the globin-verdohaemichromogen formation with the extracted solution of liver was rather inferior to the use of the mixed solution of the above reextracted solution in same dosis at first, but it was remarkably promoted with prolongation of the foregoing hours and was exceeded hourly and also temporarilly in dosis. 6. Adding haemoglobin solution or physiologic saline into the extracted solution of spleen in same dosis or adding haemoglobin solution into the same dosis of physiologic saline solution with the dosis of spleen extract and being acted with the same dosis of liver extract to the above solutions after 24 hours, the formation of globin-verdohaemichromogen was trace on the use of the mixture of the extracted solution of liver and spleen and physiologic saline, was 13 times as much as the above on the use of the mixture of the liver extract, haemoglobin solution and physiologic saline, and was 20 times as much as the first on the use of the mixture of the extracted solution of spleen and liver and haemoglobin solution, and the times obtaining of the maximum dosis were remakably shortened in the above examined order. 7. The formation of pyridin-verdohaemichromogen and globin-verdohaemichromogen with the extracted solution of the guinea pig liver, as the extracted solution of guinea pig spleen was previously acted by pyridin-haematin or haemoglobin for a long time was promoted and it's influence was great to haemoglobin.