In the eagerness with which these bones are crushed, spicula or large pieces of them become wedged between the molar teeth, and form an inseparable obstacle to the closing of the teeth.
In some cases I have found spicula projecting from the inner plate of the skull, and pressing upon or even penetrating the dura mater.
These fibres, aggregated, and connected by others, soon formed a texture of spicula or thin plates.
Here the spicula were arranged longitudinally, parallel to the axis of the bone: preserving the general form of the cartilage which constituted its scaffolding.
Professor Schulze has informed me that these spicula are developed in mesoblast cells; while the horny fibres of the sponge are developed as cuticular products of special mesoblast cells (spongioblasts).
The shell appears first of all during larval life in the form of spicula on the middle and sides of the head, and later on the middle and sides of the post-oral mantle plates (fig.
One remarkable feature in the development of the Silicispongiae is the appearance of spicula between the ciliated cells and the central mass, while the larva is still free.
In this part of the mesoblast silicious spiculaare formed.
The original spiculaare displaced to the sides, where they partly remain, and are partly replaced by new spicula.
In the later stages calcareous spicula become developed on the tentacles.
While the ciliated bands are still at their full development, the calcareous skeleton of the future calyx makes its appearance in the form of two rows, each of five plates, formed of a network of spicula (figs.
He finds that the calcareous spicula develop in these cells as in the mesoblast cells of sponges.
Some of them remain amoeboid, attach themselves to the skin, and form part of the cutis; and in these cells the calcareous spicula of the larva and adult are formed.
Spicula all (or nearly all) geminate and triradiate, composed of a long simple axial rod and three simple needle-like shanks on each end of it.
Geminate spicula double-triradiate, like those of Sphaerozoum punctatum, composed of a simple, short, axial rod and three simple pointed shanks on each end of it.
The numerous thread-like spicula of this species are so densely packed around the central capsule, that they extend all around its surface like the network round a balloon.
Often few furcate or four-rayed spicula are intermingled, or some of the spicula are smooth.
Often few furcate or four-rayed spicula are intermixed, or few spicula are not smooth, but thorny.
It {35}differs from the latter by the possession of spicula in the calymma.
Spicula all or partly geminate, consisting of one middle or axial rod, from the two poles of which diverge two, three, or more shanks in different directions.
Spicula all geminate-triradiate, with a stout and short middle rod and three arborescent shanks on each end of it.
Spicula all (or nearly all) of one kind, geminate-radiate, with a simple middle rod and two to four diverging shanks on each end of it.
The fleshy mass is of a spongy texture, full of branching water-canals, and containing a multitude of calcareous spicula of characteristic forms.
The spicula here are very varied and interesting, comprising some curious and unusual forms.
The spicula of the flesh have three rays in one plane, and one standing up from it; very stout, sharp-pointed, with a distinct canal running through the centre of each ray of the larger ones.
Cowhage has been administered with success as an anthelminthic, as has likewise spun glass pounded; the spicula of these substances destroying the worms.
The skeleton of Plagonium exhibits therefore the same remarkable form which is found in the isolated spicula of numerous #Beloidea# (e.
Spicula of exactly the same form are also found in some #Beloidea#.
Whilst in these two latter genera the six spines arise from a common central point, they arise here in two divergent groups from the two poles of a horizontal common middle rod, similar to the spicula of many #Beloidea#.
Their cavity is filled by jelly, and seems to be open at both ends, since the purified and dried spicula constantly become filled by air.
The stratification of the concentric cylindrical lamellae, which surround the narrow axial canal, is effected by the gradual deposition of the concentric layers, and is very similar to that which is found in the thick spicula of many sponges.
The slender spicula of the Cannobelida are cylindrical or spindle-shaped, tubular, scattered in variable numbers, but always in a tangential direction on the surface of the calymma.
The fracture extended through the orbitar plate of the right os frontis, over which lay two small spicula of bone; and a similar fragment was situated over the right optic nerve.
There was a hole in the right parietal bone, capable of admitting the point of the little finger, and many loose fragments of bone were felt lying on the dura mater; a trephine was applied, and numerous spicula were removed.
At the College of Surgeons the base of his tusk is still shown, with a spicula of ivory pressing into the pulp.
The sawn base of the inflamed tusk shows a spicula of ivory pressing into the nervous pulp.
It forms a small disk, the fortieth part of an inch in diameter, and having its spicula already coloured red.
Numerous geminato-radiate spicula and spherical xanthellae lie between the capsule and the including thick-walled alveole.
The spicula are scattered throughout the alveolate calymma.
The spicula lie between the alveole and the capsule, which includes a central oil-globule.
A single central capsule, with a central oil-globule, surrounded by numerous spicula and spherical xanthellae.
These spicula are of the same diameter throughout their length; they are easily detached, so that the object-glass of the microscope soon becomes scattered over with them.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "spicula" in a variety of sentences. We hope that you will now be able to make sentences using this word.
