210 Prof. G. Gulliver on the Fibrin and Latex of Vegetables. 
or properties of the latex appear interesting :—first, that 
the plant-juices may afford some help to classification; and 
secondly, as regards the most recent doctrine as to the cause of 
the coagulation of the blood. Thus we have seen a very charac- 
teristic and plain fact in the latex of Euphorbiacez. Nor is it 
any longer doubtful that a mere microscopic part may show 
the difference, even more generally than any one single and large 
character whatever, between two great divisions of the animal 
kingdom. For, since the publication of my observations, in the 
Appendix to the English version of Gerber’s ‘ Anatomy,’ it has 
become generally admitted that the presence or not of the nu- 
cleus in the red corpuscle of the blood of Vertebrata is a true 
difference between Mammalia and the three lower classes, and 
that this simple character is applicable to all ages, sexes, and 
conditions—of course excluding that early period of intra-uterine 
life when, as I have long since shown, the temporary red cor- 
puscle of Mammalia is the true analogue of the permanent red 
corpuscle of oviparous Vertebrata. And, to revert to the vege- 
table latex, Mr. Babimgton, who has so much advanced our 
knowledge of British botany, has already adopted specific cha- 
racters derived from the colour of the juice in the genus 
Papaver. 
As to the cause of the coagulation of the blood, any theory 
that does not include the fibrin of other parts is not likely to 
prove satisfactory. Dr. Richardson, in his elaborate and valu- 
able work, assigns as the cause for that coagulation the evolu- 
tion of the volatile alkali; and I believe his view already passes 
current in some of our systematic treatises. Now, I have tested 
these vegetable juices so often, and always in vain, for ammo- 
niacal vapour, that I believe the fibrin in them coagulates quite 
independently of any evolution of ammonia. Besides the 
microscopic test, so much insisted on by Dr. Richardson, other 
trials were made, like those described by Dr. Davy (and with the 
same negative results) in his examination of coagulating blood. 
And so I found, too, in spontaneously coagulable mixtures of 
serum; no eyolution of even a trace of ammonia could be de- 
tected during the coagulation. These observations are not ad- 
duced as conclusive against this chemical view of the cause of 
the coagulation of the blood, but merely as examples of the 
obstructions which at present lie in the way of a free admission 
of that view. 
Edenbridge, Jan. 31, 1862. 
