74 Transactiom of the Uoyal Mieroscopleal Society. 
form is round or slightly oval. Being subsequently treated with 
water, the same changes are observed to take place on the blood- 
corpuscles as when treated by this liquid in their fresh condition ; 
that is, the minute granules in their interior are dissolved and the 
corpuscles appear clear with pale contours. The nucleus is seen to 
swell, while the large granules it contains are dissolved, giving to 
the whole a pale homogeneous appearance. In a number of cases 
also, the delicate membraneous layer of the corpuscles bursts, 
allowing the nucleus to escape as before described. If now, after 
the blood-corpuscles have passed through these various changes, 
produced by the chloroform liquid and the water, they are finally 
treated with a weak solution of chromic acid, nearly the same 
changes will be witnessed as are produced by this reagent on the 
fresh blood-corpuscle, namely, the size of the corpuscle becomes 
still more reduced, the faint delicate double contour, together with 
that of the nucleus, appears darker and more distinct, and the 
contents of the nucleus are rendered finely granular; in some cases 
even, its original larger granules are observed to reappear. 
Diluted acetic acid discolours the blood-corpuscles and causes 
them to swell. Their outlines are then represented by pale 
greenish, delicate double contours, and in their interior numerous 
granules of the same tint are observed, which disappear by the 
continued action of the acid, or when applied in a stronger form. 
Eventually the membraneous layer, distended by the reagent, 
contracts again, and the blood-corpuscle reassumes its original form, 
or, as observed in a number of cases, its outlines appear wrinkled 
or otherwise irregular. Frequently the nucleus leaves its central 
position, and floats about in the interior of the corpuscle, or may 
escape through a rupture of the membraneous layer. The granules 
within the nucleus are observed to swell ; but while some coalesce 
and fuse to a certain extent with each other, assuming a worm- like 
or varicose form, others preserve their original shape and indi- 
viduality. The double contour of the nucleus disappears, and a 
dark single contour takes its place, which appears as if belonging to 
the fused granules ; for those not fused are bordered by one of the 
same character. Around this dark contour a slightly reddish zone 
in the form of a border is observed, which I suppose to represent 
the wall of the nucleus, altered by the reagent (Fig. 27). The 
granules of the nucleus, after having been once exposed to the 
action of the acetic acid, seem to resist the solvent action of 
water. 
When the coloured blood-corpuscles of the Amphiuma are 
exposed to the action of a 2 per cent, solution of boracic acid, they 
are gradually rendered colourless. The double contour, which 
appears very distinct, is of a greenish tint. The nucleus also is 
very pale, but shows distinctly its granules and double contour. 
