THEIR CAUSES, NATURE, AND PREVENTION. 191 



or of certain important elements thereof, and especially dimi- 

 nution of its red cells (ancvtnia), in which debility is the 

 marked feature, and in which blood medicines (phosphates, iron, 

 and cod-liver oil) are required. 



2. Those marked by excess of the normal elements of the 

 blood, either of its fat-forming or flesh-producing materials, or 

 both {hypercemia), and in which congestion, inflammation and 

 hjBmorrhage are apt to occur in one or more of the important 

 organs of the body, as the liver, lungs, and intestines ; and in 

 which some exciting cause, such as cold, is alone required to 

 determine an attack : in these, depletives (as bleeding with 

 laxative and saline alteratives) are required. 



3. Impoverishment and degradation of the hlood(spanwmia), 

 the degraded matter being passed out by the glands of the 

 bowels, producing diarrhoea or dysentery ; or by the kidneys, 

 producing albuminous or bloody urine or diabetes; in which 

 dropsies are of frequent occurrence (as in tvater-braxy), and in 

 which blood medicines, restoratives and alteratives, are required. 



4. A depraved condition of the blood, usually due to the 

 action of putrefactive germs producing blood poisoning (toxi- 

 ccemia) ; marked by rapid effusions of water and blood into 

 the system and rapid putrefaction, as in stinking ill or red 

 braxy ; and in which medicines are of little use, though anti- 

 septics and stimulants may be given. 



In addition to blood diseases proper we have also to notice 

 those due to parasites. 



Disease-producing (pathogenic) parasites form two classes, 

 viz., vegetable and animal parasites. 



Vegetable parasites are again subdivided into two important 

 classes — (1) Moidcl fungi (hyphomycetes and blastomycetes) ; 

 (2) fission or cleft fungi (schizomycetes); and in reference to 

 these fungi the remarkable fact may be noticed that they are 

 identical in form (morphologically) with the fungi by whose 

 agency the various processes of decomposition of organic matter 

 in the soil are carried on ; the former class requiring a liberal 

 supply of oxygen, are found on the surface, the latter in the 

 deeper strata of the soil. 



Those fungi which are engaged in such beneficent processes 

 as the breaking up of organic matters for the use of vegetables 

 are, so far as we know, innocent in character or non-pathogenic ; 

 but grave doubts have been entertained by many as to their 

 innocency under all circumstances ; indeed, some pathologists 

 insist that innocent organisms do sometimes contract destruc- 

 tive properties and it would be difficult to prove otherwise : if 

 there is any truth in the theory of evolution as applied to the 

 higher there is no reason why the theory should not apply 

 equally to the lower organisms. 



