152 THE MICROSCOPE. ) 
become indistinct while the elastic net-work is brought clearly 
into view. 
ADIPOSE TISSUE. 
A small piece of ordinary fat tissue is placed on a slide and 
slightly teased in water with needles. Examined with a low 
power, the globular fat cells are seen together with larger and 
smaller droplets of free fat that have escaped from the ruptured 
globules. 
Place some of the tissue in Miiller’s fluid and vomplete the 
hardening in alcohol. Make thin sections, stain with magenta, 
or hematoxylin, and mount in glycerine or after clearing, in 
balsam. If the tissue has been previously injected the pecu- 
liar net-work of capillaries will be well shown, as also their 
relation to the lobules and cells. 
Take a small portion of the omentum of a cat, wash in 
water, and stain with a 1 per cent. solution of osmic acid; a 
deep black color is given to the fat. Examine the white fibrous 
tissue from the axilla after being injected with osmic acid as 
recommended above by Cole. To study the development of 
fat cells, some fresh subcutaneous tissue should be taken from 
the foetus of any mammal, and treated with a 1 per cent. solu- 
tion of osmic acid for 24 hours, after which it may be stained 
slightly with eosin. Numerous cells will be seen in which are 
only small droplets of fat stained a deep black, while others 
will be found in which no fat has yet appeared. 
CARTILAGE. 
For the study of hyaline cartilage nothing can excel the 
preparations obtained from the thin cartilage projecting from 
the sternum of a recently killed young newt. Any tissue cov- 
ering the cartilage is easily removed and many times the speci- 
men is thin enough for immediate examination. It is moistened 
with a drop of the normal saline solution and examined with a 
4 inch objective. Remove the salt solution and add a drop of a 
5 per cent. solution of acetic acid. Now the nuclei become 
more granular and distinct. 
Most beautiful specimens are prepared as follows: 
A thin section is made from the head of the femur of a 
recently killed frog and placed ona slide and covered witha 
