093 
\ SERIES OF ESSAYS ON THE BLOOD, BLOOD¬ 
VESSELS, AND ABSORBENTS. 
By Mr. R. Vines, F.S., Royal Veterinary College. 
No. V 
The Nature and Functions of the Lymphatic and Lacteal 
Absorbents (continued.) 
On taking- a survey of the creation, we find that there exist a 
variety of different animals, in which both absorption and depo¬ 
sition are going on, and yet throughout their circulatory system 
there is not the least particle of red blood to be seen. Animals 
of this kind are without a brain and spinal marrow, and are de¬ 
nominated transparent or while-blooded: they are, by compara¬ 
tive anatomists, divided into different classes, or great families, 
as the moil use a articulata *, 8cc. 
If from white animals we turn our attention to such as are 
* These are the varied classes of animals in which it is stated that the 
lymphatic absorbent vessels have not, as 3 et, been discovred; and yet physiolo¬ 
gists are well aware that these animals possess a circulatory system of ves¬ 
sels, which, in many, as In the higher orders of animals, may be seen by 
the naked eye ; and they are also well aware, that there is absorption and 
deposition continually going on, yet they do not admit that there is a sepa¬ 
rate system of vessels set apart for that sole purpose , as in those of the higher 
orders of animals, or, in short, as in those in which both red and white 
blood are known to circulate. 
The fact is, Mr. Hunter’s theory, as regards the white or transparent veins, 
more commonly called the lymphatic absorbents, from considering them as 
neither belonging to the arterial nor the venous system, but a distinct and 
separate system of vessels, viz. the sole absorbents of the body, and that 
the red or real veins had nothing to do with that function w hatever, has, in 
my idea, been the means of leading them into error. 
The reason of the lowest orders of the animal creation possessing so sim¬ 
ple a system of vessels, appears to me very evident; namely, that these 
animals have their blood only of one qithlitjf, such as transparent or white; 
they, therefore, require only such a system of vessels as are the best adapted 
for the circulation of transparent or white fluids, and these, I should say, 
are a simple system of transparent arteries and veins, of tfie same character 
as those vessels which belong to all the transparent or while parts of such ani¬ 
mals which possess blood of different qualities, such as white and red. 
H cnee, then, as in w hite-blooded animals there is only one kind of blood 
and one kind of bloodvessels, and those of the most simple form, such as 
serous arteries and veins, these latter, I contend, are similar in character, 
and of the same nature, as the transparent or serijerous absorbent lymphatic 
veins which belong to all the different classes of animals of flic higher or¬ 
ders of the creation, and which possess blood of different qualities, as white 
and red. 
VOL. V. 
0 A 
