for a
group of tissues of very variable character. It is usually described as
consisting typically in the mammals of three chief elements felted
together; of comparatively unmodified corpuscles (c.c.), more or less
amoeboid, and of fibres which are elongated, altered, and distorted
cells. The fibres are of two kinds: yellow, branching, and highly elastic
(y.e.f.), in consequence of which they fall into sinuous lines
in a preparation, and white and inelastic ones (w.i.f.), lying in parallel
bundles. Where the latter element is entirely dominant, the connective
tissue is tendon, found especially at the point of attachment of
muscles to the parts they work. Some elastic ligaments are almost
purely yellow fibrous tissue. A loose interweaving of the three
elements is areolar tissue, the chief fabric of mesentery, membrane,
and the dermis (beneath the epidermis). With muscle it is the material
of the walls of the alimentary canal and bloodvessels, and generally it
enters into, binds together, and holds in place other tissue. The
connective tissue of fishes displays the differentiation of fibres in a far
less distinct manner.

Section 66. Through connective tissues wander the phagocytes,
cells that are difficult to distinguish, if really distinct, from the white
blood corpuscles. These cells possess a remarkable freedom; they
show an initiative of their own, and seem endowed with a
subordinate individuality. They occur in great numbers in a tissue
called, botryoidal tissue (Figure XIV.), which occurs especially in
masses and patches along the course of the alimentary canal, in its
walls. The tonsils, swellings on either side of the throat, are such
masses, and aggregates occur as visible patches, the Peyer's
patches, on the ileum. It also constitutes the mass of the vermiform
appendix and the wall of the sacculus rotundus; and in the young
animal the "thymus gland," ventral to the heart, and less entirely, the
"thyroid gland," ventral to the larynx, are similar structures, which
are reduced or disappear as development proceeds. It is evident that
in these two latter cases the term "gland" is somewhat of a
misnomer. The matrix of botryoidal tissue is a network of stretched
and hollowed connective tissue cells-- it is not a secretion, as
cartilage matrix appears to be. During digestion, the phagocytes prowl
into the intestine, and ingest and devour bacteria, that might
otherwise give rise to disease. In inflammation, we may n