On the Manganese Content of Transplanted Tumours. 175 



much larger quantities of manganese than the vertebrates, and of the verte- 

 brates the mammals contain the smallest amounts — a few hundredths of a 

 milligramme per 100 grm. of the total weight of the organism — while the 

 birds, reptiles, batrachians, and fishes show 5-10 times as much. 



The quantitative distribution in the different organs, tissues, and animal 

 products, especially of the higher classes that have been studied, is very- 

 interesting. The blood, for example, contrary to the claims of most previous 

 investigators, has been found to contain much smaller amounts of manganese 

 than sometimes admitted, usually only a few hundredths of a milligramme 

 per litre. The haemoglobin of horse blood contains no manganese. Of the 

 organs and tissues of principal functional importance higher manganese 

 values have been met with in the liver (0"265-0416 mgrm. per 100 grm.) 

 and in the kidneys (0-063-0'238). Lower values are found in the muscular 

 tissue «0-005-0-018), the nervous 'tissue (< 0-005-0-036), and the lungs 

 (0 - 006-0'023). The organs of the birds are generally richer in manganese 

 than those of mammals, and the highest value obtained has been for the 

 oviduct of birds (0-786-2-201). 



It may be mentioned that the grey matter of the ox brain is much richer 

 (0'022) in mauganese than the white (< - 005), and also that, in general, the 

 heart and muscles of the tongue contain larger amounts of this metal than 

 the trunk muscles and the muscles of the extremities. 



Among the organs or tissues of minor functional importance, the hair, 

 plumage, and nails contain relatively large amounts of manganese 

 (0-111-3-214). 



The milk is very poor in manganese, although apparently richer than the 

 blood. In the egg-white (fowl and duck) they were unable to detect this 

 metal, even when analysing 100 grm. of the fresh substance. The yolk seems 

 to contain all the manganese present in the egg. 



Considering the ubiquity of manganese throughout the animal kingdom, 

 and its remarkable distribution in the various tissues, these authors 

 emphasise the importance that it probably has as a catalytic agent of living 

 matter. Again, the wide differences shown to obtain between the amount 

 of manganese found in plants and in animals is an observation which may 

 have considerable importance. The quantities of manganese present in the 

 various organisms and tissues may very well be taken into consideration in 

 studying the problems of the origin of species, as well as those of bio- 

 chemical adaptation to the medium, in interpreting the influence of vegetarian 

 and flesh diets, and finally in drawing deductions as to the nature of the 

 physiological soil. 



In connection with Bertrand and Medigreceanu's work on manganese, it 



