THE BLOOD AND THE LYMPH. 703 



222. Of the Blood. The blood, so long as it is circulating in the 

 vessels, is a slightly glutinous fluid, in which only two elements, the 

 blood-corpuscles, -globules, -cells (corpuscula s. globuli s. cellulce sangui- 

 nis), the majority of which are of a red color while some are white, and 

 the colorless blood-plasma (liquor s. plasma sanguinis), are to be distin- 

 guished ; when excluded from the circulation, it usually coagulates en- 

 tirely, by the solidification of the fibrin in solution in the plasma, and 

 afterwards by the contraction of the coagulated constituent, divides into 

 the " crassamentum" and "serum." The former is of a deep red color 

 containing, together with the fibrin, almost all the colored, and most 

 of the colorless blood-corpuscles, with a portion of the still dissolved 

 parts of the plasma, whilst the remainder of the latter, together with 

 some of the colorless blood-corpuscles, constitutes the serum. In cer- 

 tain cases in Man, especially in disease, before the coagulation of the 

 blood has taken place, the colored corpuscles subside more or less deeply 

 below the surface of the fluid, when the crassamentum presents a super- 

 ficial colorless, or whitish stratum (inflammatory crust), consisting only 

 of the coagulated fibrin and colorless blood-cells, together with the fluid 

 with which they are imbued. 



The colored or red blood-globules, or simply blood-globules, in which 

 alone the coloring matter of the blood resides, are minute non-nucleated 

 cells of a flattened, lenticular form, which are 

 contained in the blood in such vast quantity, that 

 unless it be diluted with serum, they do not 

 readily admit of exact investigation,* appearing 

 of themselves to constitute the blood. However 

 important it would be to know accurately the 

 proportion of the blood globules to the plasma, 



their number and their volume, all researches hitherto have failed, owing 

 to the difficulty of the subject ; and even the very recent statements of 

 Schmidt, according to which 47-54 parts of moist blood-globules exist 

 in 100 parts of human blood, can only be described as approximative. 

 One method only can be successful, consisting in the direct enumeration 



FIG. 291. Blood-globules of Man : a, viewed on the flat surface ; 6, on the edge ; c, united 

 into rouleaux; d, rendered spherical by the addition of water; e, rendered colorless by the 

 same agent ; /, blood-globules shrunken by the drying up of the fluid. 



We have already pointed out the occurrence of similar amaba-like movements in the young 

 cells of mucous membranes detached during slight inflammation, and in the cells of the 

 gelatinous tissue of medusae; and we think that, very probably, it will eventually be found 

 to be a property of all young periplastic substance. 



MM. Guerin-Meneville (1849-51), Davaine (1850), and Robin (1853), appear also to have 

 observed these amceba-like movements, without being acquainted with Mr. W. Jones's essay. 

 (See the " Histoire nat. des Vegetaux parasites," by M. Robin, p. 507). TRS.] 



* [We must caution the reader against being guided by this statement. Nothing is easier 

 than the examination of the blood as it is, nothing more likely to mislead than the practice 

 of diluting it with any fluid whatsoever. TRS.] 



