379 
whilst no nucleus could be detected in them, the others 
exhibited then a granulated body and a clear pellucid nucleus 
which was coloured red by hemoglobin as in fig. 14 c. 
The third type of ammonia-action was seen in some cor- 
puscles which at first exhibited a tendency towards the 
second type, the zooid partially contracting; instead, how- 
ever, of remaining in this state, the edges of the corpuscles 
and of their contracted zooids began to break up, as seen in 
fig. 11 a, and particles separated from them and floated about 
exhibiting Brunonian movements. Larger particles separated 
in many cases, and in these it was quite easy to recognise 
the well-known double rhomboid form of hemoglobin crys- 
tals. This observation is exceedingly curious, since it de- 
monstrates a readiness of the material of the blood-corpuscle 
to assume the crystalline form which was only known pre- 
viously in some mammalia. Beale has figured (loc. cit.) from 
the guinea-pig corpuscles disintegrating into small crystals, 
just as I have here seen them in the frog; but in that case 
the phenomenon was independent of ammonia or other 
reagents; also the crystals so formed were the so-called 
tetrahedral or sphenoidal forms characteristic of the guinea- 
pig’s blood.'' I have not been able to reproduce this crystal- 
line disintegration of the corpuscles at pleasure, though I 
obtained it in several successive experiments from the blood 
of a frog in the spring of this year, at Leipzig. 
Whilst the corpuscles were undergoing this disintegration, 
in one case I passed acetic acid vapour into the chamber, 
with the result depicted in fig. 11 6. The body of the cor- 
puscle appeared to retain its hemoglobin, and was coloured 
red; the nucleus became round and was pellucid; round it, 
however, was a very intensely marked ring, due to coagula- 
tion by the acid, and in its middle one two or three sharply 
cut coagula were seen. 
These various effects of the action of ammonia in small 
quantities require explanation, in view of the chemical con- 
stitution of the various parts of the oviparous red blood-cor- 
puscle. They appear to demonstrate that the wall of the 
corpuscle is readily soluble in ammonia, and more so in some 
physiological conditions than others, the amceboid figures 
produced under the action of ammonia being due to the 
1 I may take this opportunity of mentioning that in a specimen-of the 
annelid Zubifer rivulorum, mounted in glycerine jelly, I obtained crystals 
of Hemoglobin in the drops of the red vascular fluid of the worm expressed 
in the preparation. The crystals in one and the same preparation exhibited 
three of the forms seen in different mammalia, viz. rhomboid prisms (dog, 
man), sphenoids (guinea-pig) and hexahedral plates. 
