APPEARANCES OF THE RED BLOOD-CORPUSCLES, 159 
mentioned, in some cases showing very distinctly, an elaborate 
structure, a network of internuclear fibres, some of them per- 
forating the limiting membrane, which is very distinct, and its 
appearance quite inconsistent with its being merely a patholo- 
gical change as asserted by the author; moreover, the appearances 
caused by treatment after Beetticher’s methods have been clearly 
and fully explained, and accounted for in a paper in a subse- 
quent number of the same journal.! In some cases, too, the 
nuclei may be seen clearly dividing, though as my own observa- 
tions were made chiefly upon summer and autumn frogs these 
instances were few. Preyer, however,” describes and figures this 
division of the nucleus in the blood of frogs during the breeding 
season. After discussing the question of the contractility of the 
red corpuscles, and whether they possess a cell wall, in the 
proper sense of the term, the author describes the appearances 
which are the immediate subject of this paper. Following 
Preyer, he first examined extravasated frogs’ blood, and found 
numerous processes, short points, and long straight filaments, in 
short, exactly the appearances above described; and mentions 
their production similarly by the action of urea and of heat. Also 
that similar processes are thrown out in cases of fever, especi- 
ally typhus; and that with a bodily temperature of 39-40° C., they 
occur at the temperature of the chamber; and in recurrent fever, 
as first described by Haidenreich in 1871, long filamentous pro- 
cesses of great length, extending over the whole field of the 
microscope, appear. These have been regarded as independent 
organisms, a form of Bacteria, and named Spirochete Obermeieri, 
or Recurrentis, as which they are described by Cohn.? These the 
author has observed sometimes to coalesce again with the parent 
corpuscle, and disappear. On this account he regards them as 
portions of the protoplasm of the corpuscle, which have become 
detached and endowed with independent vitality and spontaneous 
movement, but are not mere parasites. This view appears to be 
well founded, and supported by the circumstance, previously 
recorded, of their intermittent appearance in the blood, and that 
when present in vast numbers under the microscope, they again 
1 Tf the red corpuscles of human blood be treated with a five per cent 
sol. amm. chromate, the superficial appearance of a nucleus is produced, at 
least as-distinct as that which Beetticher’s methods create: the discs be- 
come “cup-shaped,” or more accurately, the shape of a soft felt hat, with 
the margin of the brim turned over, or under, all round; and as they float 
about and turn over, it becomes evident that the colourless or pale appear- 
ance of a nucleus is occasioned by the central portion of the layer of the 
corpuscle, when lying flat and looked down upon, being seen single and 
consequently pale. 
2 Loe. cit., supra. 
5 * Beit. z. Biol. d. Pflanzen,’ Bd. i, H. 3, 1875, s, 196. 
