248 
PROGRESS OF MICROSCOPICAL SCIENCE. 
Microscopy of the Blood in Infants. — M. Hayem (May 21) read 
a paper on this subject before the French Academy. He draws the 
following conclusions: — 1. When the blood of the new-born infant 
leaves the capillaries it is black, almost as much so as the venous 
blood. 2. The red corpuscles are much more unequal in size than in 
the adult ; the largest exceed the largest corpuscles in the adult ; and 
in the same way, the smallest are smaller than in the latter. 3. The 
red corpuscles of the child seem to differ but very slightly from those 
of the adult in intimate composition ; in fact, they allow endosmose, 
and lose shape more rapidly at the contact of reagents and of 
moisture ; the small corpuscles especially easily become spherical. 
4. The number of red corpuscles contained in a cubic millimeter 
is almost as high at the moment of birth as in the most vigorous 
adult, and consequently always notably superior to that of the cor- 
puscles of the mother’s blood. The average number per millimeter in 
seventeen infants was 5,368,000. The highest figure was 6,262.000, 
and the lowest 4,340,000. The result furnished by these calculations 
appears to be influenced by the manner in which the cord is tied. In 
six children who had the cord tied immediately, the average figure 
was 5,087,000. In eight children where the cord was tied only after 
the cessation of the pulsations of the umbilical artery, the medium 
was 5,576,000, making a difference of 489,000 in favour of the latter. 
5. The colouring power of infants’ blood, that is to say, the proportion 
of hfemoglobin determined by the aid of the chromometric process 
employed by M. Hayem is, on the average, as strong as that of the 
adult. 6. At the moment of birth, the same varieties of white cor- 
puscles are found as in the adult. However, these elements are a 
little smaller, and the small variety named globulines are relatively 
more abundant. During the first two or three days of life, the number 
of white corpuscles is three or four times greater than in the adult. 
The average for the forty-eight first hours was 18,000 white corpuscles 
per cubic millimeter, whilst in the adult the average of white cor- 
puscles is about 5000. 7. After birth, the blood of the child under- 
goes important modifications. In a first period corresponding to the 
diminution of the weight of the new-born infant, the number of cor- 
puscles, both red and white, remains stationary, or slightly increases ; 
when it reaches its minimum weight, that is to say usually on the 
third day, there is at the same time a sudden and considerable decrease 
in the number of white corpuscles, which fall from 18,000 to 6000, or 
even 4000, and an increase in the number of red, which generally 
reach their maximum. The rise in the number of the red corpuscles 
is very variable, from 100,000 to 600,000, and not constant. 8. From 
the time when the child begins to gain weight, the number of white 
corpuscles rises a little, it presents greater oscillations thau in the 
adult, aud remains generally higher than in the latter up to a yet 
undetermined epoch. At that time there is an average of from 7000 
to 9000. The number of red corpuscles remains definitely smaller, 
and in the course of the second week, a decrease of about half a 
million on the actual amount is found. 9. The fluctuations in the 
anatomical composition of the blood, as much in relation to the variety 
