Bauhaus-Universität Weimar

The Cyclopaedia of Anatomy and Physiology, vol. 4: Pla [corr.: Ple] - Wri
Todd, Robert Bentley
mine, for it is clear that the results of his ana¬ 
lyses may solely depend upon this fact, that in 
the animals he examined, the changes which 
I have verified in the blood globules of the 
spleen, were going on in an energetic manner. 
If these visible changes of the blood globules, 
— which certainly occur in a most exquisite 
manner in the horse and dog,—if they be nor¬ 
mal appearances, then is the diminution in the 
quantity of the blood globules, which Be¬ 
dard found on analysis, also a normal phe¬ 
nomenon ; but if not, then he only examined 
a blood partially deprived of its globules by 
stagnation and effusion. The results of che¬ 
mical analysis would then only be secure, if it 
were at the same time shown, that there were 
no visible changes of the blood globules in 
the spleens of the animals examined. Until 
this takes place, Bedard’s conclusion will 
remain, like mine, hypothetical ; although this 
is in no way diminishing the merit of his ob¬ 
servations, since I hold my own hypothesis 
as one which I am perfectly justified in pro¬ 
pounding in the present state of our know¬ 
ledge. But even if we suppose that the blood 
corpuscles are destroyed in the spleen, it is 
nevertheless a question how this dissolution 
is super-induced, and at what time it comes 
to pass. As regards the first of these points, 
in my writing previously mentioned I ex¬ 
pressed the opinion, that the spleen is a con¬ 
tractile organ, and may, by virtue of its con¬ 
tractility, be able to dilate and contract itself, 
— to fill itself with blood, and again to expel 
the blood from it. In the state of filling itself 
with blood, a stagnation of blood occurs in the 
smaller vessels, perhaps even an extravasa¬ 
tion ; and in this stagnant blood, the blood 
globules undergo destruction, since they 
slowly dissolve themselves, either free or in¬ 
closed in cells. This view I still regard as cor¬ 
rect. For, firstly, it is a matter of fact that the 
spleen does enlarge and diminish its size, and 
certainly under vital circumstances which are 
altogether normal. Very many of the older 
observers have accepted this fact ; as Lieu- 
tand, Haller, Stuekeley, Rush, Clarke, Hodg¬ 
kin, Home, and Dobson. This is shown by 
an examination of the splenic region in the 
living human subject (Piorry). So also it is 
shown by vivisection of animals, in whom 
I have myself seen (and especially in the dog) 
a very distict diminution and rounding of its 
outer surface. Finally, Landis *, by weighing 
the spleen, has recognised a distinct increase 
and diminution of weight. He examined at 
different times thirty rabbits, and finds that 
the average weight of the organ in five obser¬ 
vations was : 
12 hours after eating, 0'768 grammes 
Now although it may be freely conceded that 
* Loc. cit. 
f The “ gramme ” is 15J grains Troy English. 
an organ like the spleen is subject to so many 
variations in respect of size as to render 
thirty observations much too small a number 
to afford any very definite information con¬ 
cerning its increase or decrease of size, it 
must, nevertheless, be considered, that Landis 
has examined the proportion of the spleen to 
the whole body, and to many other organs, 
as the stomach, liver, and kidneys, and that 
from this means he derived a- confirmation of 
what the estimate of its absolute weight had 
previously taught ; so that his observations 
must be regarded as a meritorious contri¬ 
bution to our knowledge respecting the 
changes of volume which the spleen expe¬ 
riences. We now ask, secondly, how these 
changes come to pass ? Béclard states that the 
spleen enlarges and becomes filled with blood 
in consequence of the splenic vein being com¬ 
pressed by a muscular force ; but the nature 
of this he has not stated, nor can I regard his 
view as correct. I believe myself to have 
propounded a better theory when I stated, 
that the spleen becomes turgescent in conse¬ 
quence of the relaxation of the muscular 
fibres which exist in its balks, coats, and 
vessel-sheaths ; or in animals from whom 
these are absent, through a relaxation of the 
muscular fibres of the vessels themselves. 
A constriction of the splenic vein cannot be 
supposed to obtain, since the muscular fibres 
which it contains are but very little de¬ 
veloped, and no other compressing force is 
present ; while, on the contrary, we know that 
in all animals the splenic artery is uncom¬ 
monly muscular, and that the partitions of the 
spleen themselves contain distinct muscular 
fibres. It is these muscles and no others 
which, according to my researches, produce 
the distension of the spleen ; but not through 
their contracting together, but by their re¬ 
laxation, which brings with it a distension of 
the vessels with blood, and a slower circu¬ 
lation of this fluid. The diminution in the 
size of the spleen occurs simply through the 
contraction of the muscular parts just named. 
Precisely in the same manner the corpora 
cavernosa of the penis become filled with 
blood by a relaxation of the muscles situated 
in their fibrous partitions ; and become poorer 
in blood, and smaller in size, when the mus¬ 
cles again contract themselves. Of course, 
both here and in the spleen, the nerves play 
an important part in the process ; probably in 
consequence of antagonistic relations be¬ 
tween them and other parts of the nervous 
system, which at present cannot be accu¬ 
rately indicated. Thirdly, and finally, it may 
be asked, whether the blood corpuscles simply 
dissolve because the blood of the spleen be¬ 
comes stagnant at certain times, or whether 
special influences are necessary to this effect ? 
— whether the parenchyma of the spleen or 
the Malpighian corpuscles may not secrete a 
juice, a “ sulcus lietialis,” of which the earlier 
authors speak, which exerts a solvent in¬ 
fluence on the blood corpuscles ? As a kind 
of vague answer to this question, I have ex¬ 
amined the parenchyma with respect to its


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