THE BLOOD OF MAGELONA. 11 
Osmic acid coagulates the substance of the corpuscles, but 
does not otherwise change them. They only become distinctly 
brown after some minutes, and do not give the dark brown or 
black colour characteristic of fat. 
Nitric acid (25 per cent.) and Hydrochloric acid 
(20 per cent.) cause the corpuscles to become granular, 
though they do not actually disappear. The colour is changed. 
Potash (80 per cent.) has a similar action. 
Glacial acetic acid dissolves the globules, leaving minute 
granules, though the action is very slow. 
Further, picro-carmine stains the globules, as also does 
eosin: they retain their homogeneous appearance, however. 
These tests are unfortunately inadequate for the identifi- 
cation of the substance of which these globules are composed ; 
but from the ether, chloroform, and alcohol reactions, I think 
we may conclude that it is one of the “ fats ” which are soluble 
in these reagents, and moreover, give rise to crystalline bodies 
on evaporation. And amongst these fatty bodies, lecithin 
appears to give a similar reaction with water, in that it swells 
up in a peculiar way, forming droplets and threads, as I have 
described above. 
4. General Remarks. 
From these observations it will be seen that the blood of 
Magelona is totally different in structure from that of any 
other Chetopod, in that it consists mainly of very small 
madder-rose coloured, non-nucleated globules, embedded (rather 
than floating) in a very small amount of colourless plasma: 
amongst the corpuscles occur isolated nuclei. It was originally 
demonstrated by Professor Lankester that nuclei occur in the 
red fluid of the common earthworm, and this observation has 
been extended to sundry other Annelids by various observers. 
In these cases, as in Magelona, the nucleus is surrounded by 
very little, if any, protoplasm, and floats freely in the perfectly 
liquid plasma, which is coloured red by hemoglobin, or ina few 
cases green by chlorocruorin or chlorochromin ; while in some 
Oligochzetes the plasma is colourless. No other structural 
