57 

 There were found in 1,000 parts of fresli muscle of a — 



Part calcium. 



Dog -- 0.0685 



Hog - 0806 



Deer 0959 



Cat 0846 



Man 0748 



or an average of 0.0809 part calcium. On the other hand Oidtman^ 

 found in the liver, the largest gland in mammalia, 0.284 part of cal- 

 cium for 1,000 parts, or nearly three and a half times as much as the 

 average in the muscle. 



Embryos and young animals show a higher percentage of nuclear 

 mass in the muscles than do full-grown animals, hence the fact that the 

 muscles of the calf contain more lime than those of the cow^ is in full 

 accord with the writer's inference. Zoologists have further observed 

 that the muscles of fishes andbatrachia are relatively richer in nuclear 

 mass than are those of mammalia. The fact that Katz^ has found two 

 to three times as much lime in the muscles of such animals as in those of 

 mammalia is therefore strictly in accord with the writer's view. There 

 is in 1,000 parts of fresh muscle of the — 



Parts calcium. 



Frog 0.1566 



Shad 2206 



Eel - - 3913 



or an average of 0.2562 part calcium. 



The importance of lime for the division of cells even in the lower 

 animal organisms is shown by Herbst's statement^ that the most 

 important salt for the development of the sea urchin's eggs is calcium 

 phosphate, in the absence of which not even the completion of segmen- 

 tation is possible. The calcium of this salt is just as important as the 

 phosphoric acid. It happens that this salt is present in the sea water 

 in very small quantities only, hence it must be assumed that these eggs 

 have a great absorptive i:>ower for it. 



A relative increase of magnesia can be observed in certain organs 

 in which the nuclear mass is small. Thus, according to Geogehan, the 

 human brain contains about ten times as much magnesium phosphate 

 as calcium phosphate, and the muscles of mammalia contain in most 

 cases more magnesia than those of batrachia and fishes, as shown by 

 Katz's results.^ 



' Prize Treatise, Wiirzburg, 1858. This anthor found 1.1 per cent inorganic sub- 

 stance in the liver, and in 100 parts of this ash 3.62 per cent of lime and 0.19 per 

 cent of magnesia. Calculating from these data, there are contained 0.2842 part of 

 calcium and 0.0125 part of magnesium in 1,000 parts of fresh liver. 



^The lime content of the liver cells is also larger, according to Kriiger (1895), in 

 the calf than in the cow, which suggests the necessity of further microscopic com- 

 parison as to the relative size of the nuclei. 



^Loc. cit. 



^Arch. f. EntAvicklungsmechanik, Vol. V, p. 667. 



"^ Loc. cit. 



