336 
PROFESSOR POUCHET. 
from -p'oV¥ to -yw-0 They possess all the physico- 
chemical characters of the haematids. 
We are now able to understand the full importance of 
this discovery, which, perhaps, partially escaped M. Semmer. 
It shows us that haemoglobin can exist in other anatomical 
elements than in red corpuscles. M. Kiihne, before this, 
thought that the colouring matter of the red muscles of ver- 
tebrates might be haemoglobin, but he was not able to prove 
it. Now, it is easy to prove by all the usual tests that the 
granules in the leucocytes of Semmer are made of haemo- 
globin. If MM. Alexander Schmidt and Semmer have 
described them as an intermediate form between leucocytes 
and red corpuscles, this must not be understood in the sense 
that they represent a developmental stage through which 
the leucocytes pass before developing into red corpuscles : 
the leucocytes of Semmer are intermediate between the 
white and red corpuscles only in the sense that they par- 
take in a certain manner of the constitution of both. 
Probably the leucocytes of Semmer undergo a final disin- 
tegration, and the large granules becoming dispersed in the 
blood plasma soon dissolve. 
Their nuclei are always or almost always near the surface 
of the cell (which is perhaps important with regard to their 
special development), and never present any more than do 
those of other white corpuscles — any trace of decay, and 
probably become nuclei of origin. 
Nothing has hitherto gone to prove that these, originat- 
ing from a cellular body where haemoglobin is already 
formed, can be specially considered to become haematoblasts. 
First Red Corpuscles of the Embryo . — The formation of the 
first red corpuscles in the vascular area of birds has been 
studied by many embryologists, and still raises a certain 
number of important questions on which there are two 
opinions. Among oviparous holoblastic animals — the Am- 
phibia — it appears certain that the embryonic cells are 
directly transformed into red corpuscles, as they show those 
vitellin grains and small pigment granules which are seen 
in the corpuscles in their early life, and which only very 
gradually disappear. 
Blood of Mammals . — In spite of the numerous works 
which have been lately published on the number of the cor- 
puscles (Manassein Malassez, Hayem, Perier, &c.), it is evi- 
dent that the descriptions given of the elements of the blood 
are incomplete, and even inaccurate ; the characters of the 
white corpuscles badly defined, the form of the red cor- 
puscles insufficiently described, other elements altogether 
