130 ORIGIN OF GELATINE. 



most highly nitrogenised element of the food of 

 carnivora, died with the symptoms of starvation ; in 

 short, the gelatinous tissues are incapable of conver- 

 sion into blood. 



But there is no doubt that these tissues are 

 formed from the constituents of the blood ; and we 

 can hardly avoid entertaining the supposition, that 

 the fibrine of venous blood, in becoming arterial 

 fibrine, passes through the first stage of conversion 

 into gelatinous tissue. We cannot, with much pro- 

 bability, ascribe to membranes and tendons the 

 power of forming themselves out of matters brought 

 by the blood ; for how could any matter become a 

 portion of cellular tissue, for example, by virtue of 

 a force which has as yet no organ? An already 

 existing cell may possess the power of reproducing 

 or of multiplying itself, but in both cases the pre- 

 sence of a substance identical in composition with 

 cellular tissue is essential. Such matters are formed 

 in the organism, and nothing can be better fitted 

 for their production than the substance of the cells 

 and membranes which exist in animal food, and 

 become soluble in the stomach during digestion, or 

 which are taken by man in a soluble form. 



20. In the following pages I offer to the reader 

 an attempt to develope analytically the principal 

 metamorphoses which occur in the animal body; 

 and, to preclude all misapprehension, I do this with 

 a distinct protest against all conclusions and deduc- 

 tions which may now or at any subsequent period be 



