Connective Substances. By T. E. Satterthwaite. 247 
able time. These networks are beautifully sbown by taking the 
mesentery of the frog in contraction and immersing it in acetic 
acid. The fibrillated connective tissue will swell up and become 
invisible while the elastic fibres will be unaffected. The ligamentum 
nuchse also affords an excellent opportunity for studying this tissue 
by itself. To render this study more easy the tissue may be 
allowed to remain a few days in a 10 per cent, watery solution of 
common salt, and it may then be more easily teased. In the sub- 
cutaneous connective tissue of the skin the elastic fibres are well 
shown by hsematoxylin preparatioDS. Being unaffected by this 
staining solution they appear as bright, silk-like cords, which lie in 
close apposition with the wavy bundles, and the branches arch over 
the bundles to anastomose with corresponding branches of other 
bundles, so that in this way meshes are formed. Some writers 
have spoken of little knobs at the nodal points of the meshes, but 
these appearances appear to have been illusory. 
Eecklinghausen seems to have believed,* with Yirchow, that 
the elastic fibres contain peculiar nuclei of their own, which in 
adult tissue become extremely small, and are represented by the 
dark markings seen in such tissues. Thin claims {luc. cU.) tbat 
they originate in branching corpuscles which by their coalescence 
form the network, and the remains of the nucleus may be shown by 
hsematoxyhn. These markings may, it is true, be seen in the 
ligamentum nuchse of the ox, but it is doubtful whether they are 
nuclei or mere clefts in the tissue. Examination with such high 
powers as Gundlach's No. 15 immersion and Wales's xoth fails 
to clear up this point. We may now review these substances 
as a whole, and decide as to the characters they have in common. 
Elastic tissue, having a wholly different significance from the 
others, will be treated separately. 
1. The most constant form that is met with in all these tissues 
is a somewhat flattened ovate or rhomboidal body that assumes the 
colouring matter deeply. It is found in each tissue \ve have 
enumerated. In some, as in the fibrillated connective tissue, it is 
often larger and flatter than in others, as the tendon tissue, but 
this difference appears to depend upon certain conditions which 
modify the original form. For example, when the tissue is young 
or inflamed, these corpuscles are larger, more vesicular, and closer 
together, and have better defined edges ; when, on the other hand, 
the tissue is older or in a state of comparative inactivity, as in 
ordinary health, these bodies are shrunken and irregular, and 
conform more to the precise locality in which they are placed ; they 
are also farther apart, and often are hard to discover at all — facts 
which serve to explain the statements of Waldeyer, who says that 
these corpuscles are often paddle-wheel shaped, and instead of con- 
* ' Cellular Pathology,' 1871. 
