242 On the Structure and Development of 
sections, wliicli stain in the following solution of lisematoxylin for 
twenty-four hours : 
Hsematoxylin gr. lii. 
Aluminis Jj. 
AquJB 3 viij. 
M. and strain. 
Wash in distilled water and mount in glycerine, tease with needles 
and examine with a high power ; there will then he no difficulty in 
seeing that the delicate supporting substance of both grey and 
white matter consists of fibres. They may even be distinctly 
isolated, for the colouring matter darkens them somewhat, and they 
become hardened at the same time, so as to be somewhat stiff and 
unyielding. Then it will be seen that many fibrils are disposed in 
parallel rows which, perhaps, can hardly be called bundles, but 
rather thin laminae ; other similar fibrils cross them at various 
angles, giving to the whole, with a moderately high power, the 
appearance of a very delicate mesh work (a). It does not appear 
as if the fibrillae anastomose with one another, though this point 
would be extremely difficult to settle. It must be stated that 
possibly some of these fibrils may be nerve elements, though this 
seems doubtful, because they do not even seem to be connected with 
the nerve fibres that are distinctly shown by this method of pre- 
paration. In the drawing they are not represented, to avoid con- 
fusion. Of course, granular appearances are always noted in the 
brain, but this must be the case when cross sections are made of the 
delicate fibrillse. Three are three kinds of corpuscles met with in 
the brain and medulla. The first are the variously shaped gan- 
glionic corpuscles or cells (bhh), then the ordinary lymphoid 
cells (c c), which here are generally seen to have a pale envelope 
about them ; lastly, smaller corpuscles (d d) of irregular shapes, and 
many of them undoubtedly flattened md appearing to have branch- 
ing processes {d). They may be found in considerable numbers, 
and can be isolated, so that there is no doubt that they exist. The 
fibrillse of the neuroglia do not difier substantially in size from the 
fibril Ise of fibrous tissues elsewhere. 
5. Tendon Tissue (Fig. 1, Plate CLYI. [Oct. No.]).— Tendon 
tissue may be well studied in the gastrocnemius of the frog. It is 
prepared like the precedmg. If, however, it is desirable to show the 
nuclei in adult tissue, it is well to use nitrate of silver. Cut a thin 
section of a fresh tendon and expose it for a few minutes in a one-half 
per cent, solution of nitrate of silver, until the section is turbid or 
milky, then place in the sunlight, and in a few minutes the turbid 
colour will give place to dark brown or black, owing to the deposit of 
silver, and the tissue may then be mounted in glycerine and examined. 
This method will show the corpuscular bodies to advantage. In some 
