The inner surface of their cup-shaped mouth is armed with pointed teeth, with which they perforate the integuments of the fish attacked, scraping off particles of the flesh and sucking the blood.
Of endophytes a distinction must be made between those which occupy the cell-wall only and those which perforate the cells, bringing about their destruction.
(C original; the rest after von Koch.) aporose corals, the only communication between the cavity of the edge-zone and the general cavity of the zooid is by way of the lip of the calicle; in the latter, or perforate corals, the theca is permeated by numerous branching and anastomosing canals lined by endoderm, which place the cavity of the edge-zone in communication with the general cavity of the zooid.
The septa of modern perforate corals are shown to have a structure nearly identical with that of the secondary forms, but the trabeculae and their nodes are only apparent on microscopical examination.
- Colonial branching or palmate perforate corals, with abundant trabecular coenenchyme.
- Solitary or colonial perforate corals, branching, massive, or encrusting.
The blastopore, bl, has The extent of the shell and closed; the anus will subcommencing upgrowth of the sequently perforate the cormantle-skirt is indicated by responding area.
In old specimens some of the longer, lower teeth work their tips into deep pits, and ultimately even perforate the corresponding parts of the upper jaw.
These aggregations or colonies, as they are termed, may attached to muddy surfaces by rhizoids; Caulerpa, on the other, assume the form of a plate, a ring, a solid sphere, a hollow sphere, presents a remarkable instance of the way in which much the same a perforate sphere, a closed net, or a simple or branched filament.
The neck is long and curved, and its vertebrae are remarkable for the position of the canal for the transmission of the vertebral artery, which does not perforate the transverse process, but passes obliquely through the anterior part of the pedicle of the arch.
In others the peripheral ends of the septa are united only by bars or trabeculae, so that the theca is perforate, and in many such perforate corals the septa themselves are pierced by numerous perforations.
18, B), but the presence of the canal system in the perforate theca leads to a modification of the process.
These often have the form of prisms of calcite surrounded by a cuti cular meshwork; the whole is nourished and kept alive by processes, which in Crania are branched; these perforate the shell and permit the access of the coelomic fluid throughout its substance.
D'Orbigny's name for a genus of Perforate Foraminifera, distinguished by the flattened, lenticular discoid shell of many turns, finely perforated; chambers subdivided by incomplete septa into squarish chamberlets.
Sometimes, though rarely, the ulcers perforate the intestines, causing rapidly fatal inflammation of the peritoneum, or they may erode a blood vessel and produce violent haemorrhage.
This concentration is most easily produced by sliding or revolving diaphragms. A series of holes of different sizes perforate a revolving disk below the stage plate at an equal radial distance from the axis of the disk, so that the holes can be brought under the preparation in turn, the centre of the diaphragms always being a continuation of the optical axis of the microscope.
The life-history of Schistostomum haematobium is still unknown, but the difficulty in obtaining developmental stages in any of the numerous intermediate hosts that have been tried suggests that the ciliated larvae may develop directly in man and either gain access to him by the use of impure water for drinking or may perforate his skin when bathing.
A large number of corals, both aporose and perforate, are colonial.
- Incrusting or massive colonial perforate corals; calices usually in contact by their edges, sometimes disjunct and immersed in coenenchyme.
And movable perforate plates and perforated rings, both the movable plates being driven by the same current and revolving about a common axis.
Males have a pair of dagger-shaped horns on the forehead, the tips of which, in some cases at any rate, perforate the hairy skin with which the rest of the horns are covered.