367 
scribes effect of heat, and denies contractility to the red 
blood-corpuscle, describes small-sized corpuscles from hu- 
man blood. 
Stricker (‘ Pfluger’s Archiv,’ vol. i, 1868) describes the 
effect of alternate Co, and atmospheric air on red corpuscles 
first acted on by aqueous vapour; distinguishes the ‘“‘ body ” 
and the ‘‘ nucleus ” of the corpuscle, without prejudging the 
question of the existence of an cecoid, discusses the structure 
and varieties of form which the corpuscle exhibits. 
Addison (‘ Quart. Journ. Micros. Science,’ 1861) describes 
changes in form produced by acidity and alkalinity. 
Roberts (‘Proceedings of Royal Society,’ vol. xii; and 
‘Quart. Journ. Micros. Science,’ 1863) describes a “‘ macula ”’ 
produced by nitrate of aniline dye in mammalian and other 
red blood-corpuscles ; also a corresponding pullulation caused 
by tannin. 
Savory (‘ Proc. Roy. Soc.,’ xvii, 1868-69) denies the exist- 
ence of a nucleus in living corpuscles of oviparous verte- 
+ brata. 
Richardson (‘'Trans. American Medic. Assoc.,’ Philadelphia, 
1870) argues from the red contents separating from the con- 
tour-line as crystals within the corpuscles of Menobranchus, 
that the latter have a distinct wall. The observation is not 
new, Owsjannikow (‘ Bull. de ’ Acad. St. Petersburg,’ vol. 
viii, p. 561) having figured such, as well as other writers. 
Norris, on the laws and principles concerned in the 
ageregation of blood-corpuscles, both within and without the 
vessels (‘ Proceedings of the Royal Society,’ vol. xvii, p. 429, 
1868-69). 
Brunton, “ On the Chemical Constitution of the Nuclei of 
Red Blood-corpuscles ” (‘ Journal of Anatomy and Physio- 
logy,’ November, 1869), gives reasons for supposing mucin 
to be present; this is one of the first attempts at methodical 
microchemical investigation of the red corpuscle. 
The separately published works or essays of Kneuttinger 
and of Rindfleisch on the histology of the blood I have not 
seen, and cannot therefore speak of their contents. 
3. The normal appearance of the Frog’s red corpuscle. In 
fig. 1, plate XV, I have represented the blood discs of the 
frog. It is certainly quite impossible to detect anything like 
a membrane to these corpuscles in their fresh untouched 
condition ; what might be taken for such proving, when the 
highest powers are used, to be a refraction illusion. It has 
also been denied that in the perfectly fresh corpuscle a 
nucleus can be detected (Savory, loc. cit.). This, I think, is 
an error. It sometimes happens that no nucleus can be at first 
