4, W. BLAXLAND BENHAM. 
contour is changed by pressure. Many are ovoid, others 
circular or irregular. If studied within the blood-vessels the 
corpuscles exhibit a refringent body or nucleus-like central 
structure. In addition to these spherules various other elements 
exist, which may perhaps be explained as a development of 
spherules inside cells. Here and there a coagulum may be 
seen between the corpuscles. Treated with strong acetic acid, 
very noticeable changes occur. The whole field is now covered 
with a granular débris (Pl. 38, fig. 9), and in place of the 
corpuscles we see masses of granular cells of larger size. The 
acid probably dissolves the envelope of the corpuscles or 
alters their walls, so that the (probably fatty) contents run 
together to form larger masses.” 
It will be seen later that this description, though true to a 
certain extent, does not exhaust the subject. I may mention 
that nearly the whole of my own observations had been made 
before I had acquainted myself with the above account of the 
blood given by M‘Intosh,—that is, in reading his paper some 
time back I had not paid special attention to his statements 
as to the blood itself. 
1. Spectroscopic Examination.—A fter observing the re- 
markable change of colour on oxidation I wished to examine 
the blood spectroscopically, and to this end I sought for some 
reagent which would extract the pigment; but though I was 
unsuccessful in my attempts, yet these experiments are, I 
believe, worthy of record, as the action upon the blood of 
some of the reagents is sufficiently peculiar. These will be 
described below. 
Having been unsuccessful in extracting the colouring matter, 
I examined the blood itself by means of Zeiss’s spectroscope. 
For this purpose I compressed a worm with its introvert everted, 
so as to give a thin film of pink fluid, and examined it through 
the micro-spectroscope; but no absorption bands were visible. 
I then had short pieces of glass tubing cut and fixed to glass 
slips, so that I could fill them to a greater or less extent, and 
get a column of fluid of different depths. The process of 
obtaining sufficient blood to fill even a tube one eighth of an 
