374 LECTURE XVI. 



much more likely that the function of those cells whose duty it is to assimi- 

 late the required calcium does not exert itself normally. All the facts 

 known concerning the bones of children who have suffered from this 

 disease agree best with this conception. Above all there is a striking over- 

 production on the part of the osteoplastic tissue. This results in the 

 formation of soft bones deficient in lime, the so-called " osteoid tissue." 

 At the same time there is an abnormal resorption of the tissue already 

 formed. We cannot be far wrong, if we attribute the disease of rickets to 

 a metabolic disturbance on the part of a certain group of cells; and here 

 again the cells themselves stand in the foreground as organs of assimila- 

 tion. We may say in this connection that it is not the cells which play 

 the chief part in the assimilation of lime. The other component, which 

 we cannot yet sharply formulate according to our present knowledge, and 

 therefore designate in general by the term "plasma," is equally important. 

 We have said nothing concerning the condition of the lime in the cells; 

 and, in fact, we are not able at present to depict the calcification process 

 which takes place in the formation of bones. We do not know whether 

 the osteoidal tissue formed in the disease of rickets is capable of taking 

 up lime at all, or whether it is able to deposit calcium salts from their solu- 

 tions. If we recall what was said concerning the mutual relations of the 

 individual ions, we shall be tempted to attribute the over-production of 

 osteoidal tissue to some such influence. 1 We have seen that calcium 

 chloride, for example, acts antagonistically towards sodium chloride, and 

 have drawn the conclusion from all such observations that only by means 

 of the inorganic substances in the cell acting together do we have any 

 guarantee for the normal exercise of the functions of the cell. If any one 

 element is missing, a disturbance must necessarily follow. A certain 

 amount of opposing force is lost, and thus the action of a certain ion or a 

 group of ions exerting a similar effect may be felt. With these suggestions 

 we will merely state that all our present knowledge concerning rickets 

 leads us to the conclusion that the disease cannot be attributed to a lack 

 of lime in the diet of the child, and to-day we have no reason for assuming 

 that the lime is present in the cells of those who are suffering from this 

 disease in a form which the cells cannot assimilate. The cause of rickets 

 is doubtless much more deeply seated, and is to be traced to the organiza- 

 tion and metabolism of the cells and tissues concerned in the process of 

 bone production. The whole course of this disease, which in fact is usually 

 " outgrown," is in accordance with this view. It is not to be assumed 



1 Cf. Clowes and Frisbe, Am. J. Physiol. 14, 173 (1905), who have found that a 

 rapidly developing adeno carcinoma in mice contains considerable potash and less lime. 

 Slow development of the tumor shows the reverse proportions. It is not possible to 

 draw definite conclusions at present as to which process is primary and which secondary 

 in nature, but studies in this direction certainly warrant attention. 



