ITS VITAL PROPERTIES,, AND RELATIONS TO LIVING ORGANISM. 207 



attributed to an original want of capacity in their germs, or to some agency 

 which subsequently depresses their vital power, or to the want of some material 

 which they require for the purpose, can scarcely at present be decided ; and it 

 may be doubted whether any one of these determining causes is in action in 

 every case, or whether each of them may not occasionally operate, either singly 

 or in combination. 



197. Turning now to those constituents of the Blood which show no indi- 

 cations of possessing vitality, we have first to speak of its Albumen. The rela- 

 tions which this substance bears to the living body are of the most important 

 and fundamental character ; since, as already shown ( 20), it is the original 

 pabulum at the expense of which all the solid tissues are generated, whilst it 

 also affords the material for the production of the fibrin, the globulin, and the 

 haematin of the blood itself. It appears, however, to be itself entirely destitute 

 of formative capacity ; for in no exudation which is purely serous do we ever 

 trace the slightest indication of organization ; and its conversion into the various 

 kinds of tissue, therefore, must be entirely due to their own power of appropri- 

 ating and transforming it. 1 The great function of the Albumen of the blood, 

 then, is to supply the material for these various transformations; and we ac- 

 cordingly find that whatever other changes the fluid may undergo, whether it 

 loses its fibrin or its red corpuscles, or both, albumen is still present in abund- 

 ance. Its ultimate source is to be found in the food ; but the serous liquid 

 which percolates the tissues of the body may be looked upon as a reserve-store 

 to be drawn upon in case of need, furnishing albumen to the blood when it 

 might otherwise be deficient ; and thus perhaps it is that abstinence or repeated 

 losses of blood do not produce the degree of depression in the proportion of 

 albumen which might be expected from the very marked reduction which they 

 effect in that of the corpuscles. 2 When an excess of Albuminous matter is in- 

 gested as food, the injurious effects which might follow the too great augmen- 

 tation of this constituent of the Blood, appear to be averted by the readiness 

 with which it undergoes retrograde as well as progressive metamorphoses ; for, 

 if not speedily subjected to the latter change, it appears to be affected by decom- 

 posing agencies, and to be eliminated from the system by the excretory appara- 

 tus, under the form of urinary and biliary matter. (See CHAP, xn.) As 

 already pointed out, however, although Albumen seems to furnish certain con- 

 stituents of secretions which are applied to special purposes within the body, yet 

 its passage as such into the excretions must be looked upon as quite abnormal, 

 and as (so to speak) a mere waste of nutrient material ( 21). 



198. The Fatty matters of the Blood are obviously destined to furnish the 

 contents of the adipose and nervous vesicles; whilst their presence seems also 

 to be required in the early stages of the production of cells generally ( 42). 



1 Those who maintain that Fibrin is the only organizable constituent of the blood, and 

 that it is the immediate source of the nutrition of the tissues generally, consider that Al- 

 bumen cannot be appropriated by the tissues without first passing through the Condition 

 of fibrin. This doctrine, formerly contended for by the Author, he now abandons as in- 

 consistent with much that we know of the history of fibrin and of its destination in the 

 body ($ 192) ; and he would rest upon the simple fact that the first development of the 

 embryonic mass, by the multiplication of its component cells, takes place in a fluid in which 

 nothing analogous to fibrin can be discovered, as showing that cells are able to draw their 

 support directly from an albuminous pabulum ; whilst it is only when the gelatinous tissues 

 begin to be formed in the embryo that we find its blood to become spontaneously coagu- 

 lable. 



2 It is to be remembered, however, that the whole mass of the blood (liquid as well as 

 solid) is probably reduced under these circumstances ; it having been found by the experi- 

 ments of Chossat ("RecherchesExperimen tales sur 1'Inanition"), that when animals were 

 killed by starvation, the blood lost no less than 75 per cent, of its weight, whilst the ave- 

 rage loss of the whole body was 40 per cent. 



