448 
4. From one of the halones, about a quarter ot an inch ex- 
ternal to the germinal centre, I took a fragment, which, when 
submitted to a power of 900 D., presented the following ele- 
ments : 
a. Large flat masses ofa finely granular base or stroma, 
with superposed free granules, small vesicles, and oil-globules. 
b. A considerable number of long flat bands or fibres, with a 
very fine, clear, double outline, and minutely granular centre, 
and occasional superposed and adjacent small vesicles and gra- 
nules; here and there a small vesicle was to be found lying 
partly within and partly without the fibre. In some places 
the fibres appeared to me to terminate by tapering, indistinct 
granular ends, and I am much disposed to think that this in- 
dicates the true mode of their formation, viz., by the linear 
aggregation of granules. On the addition of acetic acid, I 
could get no indication of nuclei, or of the outlines of cells of 
any kind. 
c. The large vesicles still exist in abundance, but I cannot 
see them anywhere to be distinctly engaged in forming any 
structure; I have looked in vain for nuclei in them; there 
appear to be two varieties of them—one finely granular, the 
other containing numerous large, dark globules. I think they 
become larger and more numerous for a certain time, and then 
break up; I look upon them as a-plastic, and consider their 
most probable use to be that of forming loci for the chemico- 
molecular elaboration of or change of combination of the 
chemical elements. The fibres above alluded to were found 
in the vicinity of granules, granular masses, and a small va- 
riety of cells. 
5. In a preparation from near a blood islet I obtained a 
number of reddish-coloured elliptical corpuscles, some with 
nuclei, others without, also large finely granular vesicles, and a 
smaller kind of hyaline clearness, which burst on the addition 
of water. 
6. Inthe plasma from a cut in my finger, five minutes after 
