ALBUMEN. 347 



reproduction of effete materials. The absence of fibrin in the fluids 

 of the egg, must also be considered as opposing VogePs view, since 

 these fluids exhibit the highest degree of plasticity ; yet it must be 

 admitted on the other hand, that this counter-proof is less worthy 

 of attention from the circumstance that vitellin, which is the true 

 germ of the egg, has been found by the most careful investigation 

 to be more similar to fibrin than any other protein-compound, having, 

 indeed, an almost perfectly identical composition with it. But 

 independently of the peculiar relations of the germ of the egg, a 

 careful consideration of plastic exudations will in itself lead us to 

 doubt the correctness of VogePs view, for how can the small quantity 

 of fibrin in the plasma (see " Fibrin") give rise to the frequently 

 large accumulations of fibrinous exudations that are passing into an 

 organised condition, rapidly as the resorption of the serous portions 

 of these exudations may be effected ? We cannot suppose that 

 Vogel intends to assert that it is only the fibrin of the exudations 

 which is converted into cells and fibres. The following mode of 

 considering the subject appears to correspond most closely with 

 the facts before us. We shall in a subsequent part of the work 

 enter upon the consideration of fibrin, as a link or transition stage 

 in the metamorphosis of nitrogenous matters ; we agree therefore 

 so far with Vogel as to assume that all albumen passes through a 

 transition stage, which we term fibrin, before it can be converted 

 into cells and the elements of tissues: hence this intermediate 

 link in the metamorphosis of tissue appears in very small quan- 

 tity or not at all, because at this stage the metamorphosis is 

 stationary for only a short time. If we regard fibrin as a body 

 whose specific gravity is ever changing with its chemical changes, 

 as, for instance, is the case with the aldehydes, it would scarcely 

 remain for any appreciable length of time at a given stage of 

 metamorphism, and would therefore be as little appreciable to our 

 senses as the aldehyde of acetic acid, in the process of acid fer- 

 mentation. We therefore believe that in the organisation of the 

 exudations, fibrin is formed from the albumen of the transuded 

 plasma, but that it rapidly undergoes further metamorphosis. 



It still remains, however, for us to determine why cells and 

 fibres are not formed from serous exudations, that is to say, from 

 albuminous solutions containing no fibrin. This question might 

 perhaps be answered by supposing that the presence of fibrin is 

 only required to form the point of crystallisation for the deposi- 

 tion of plastic matter, and this view seems to derive support from 

 the fact, that a portion of coagulated fibrin when thrown into an 



