Page:EB1911 - Volume 25.djvu/690

 (unguentum nardinum sive foliatum) contained costus (the root of Saussurea lappa), amomum (the fruits of Amomum cardamomum), balm (the oleoresin of Balsamodendron opobalsamum) and myrrh, with Indian nard (Ibid. xiii. 2).

The exact botanical source of the true or Indian nard was long a matter of uncertainty, the descriptions given by ancient authors being somewhat vague, but it is now identified as Nardostachys jatamansi, a plant of the valerian order, the fibrous root-stocks or “spikes” of which are still collected in the mountains of Bhotan and Nepal. The name “spike” is applied apparently from its resemblance in shape to a spike or ear of bearded corn. The root is crowned by the bases of several stems, each about 2 in. or more in length and as thick as the finger. To these the fibrous tissue of former leaves adheres and gives them a peculiar bristly appearance. It is this portion that is chiefly collected.

SPILLIKINS (M.D., spelleken, little pin), or (originally “jerk-straws”), a game of some antiquity played with a set of slender sticks of wood, bone or ivory, from 3 to 6 in. long, generally carved to represent weapons and utensils of various kinds, which are thrown in a heap haphazard upon the table. The players then endeavour in turn to extricate from the heap, one at a time, as many straws as possible, without moving any except the one angled for. The player obtaining the most straws wins. The game is called in French jonchets and in German Federspiel.

SPINA (Lat. for a thorn, or prickle, also backbone, whence spine), in architecture, the term given to the low podium wall which divided the circus of the Romans and round which the chariots ran; at each end of it was the meta or goal. On coins, gems and bas-reliefs it is shown with numerous other features on it, such as obelisks (of which those from the spina of the Circus Maximus are now in the piazzas of the Lateran and del Popolo), small aedicula or pairs of columns carrying an entablature, altars, statues, trophies, &amp;c.

SPINACH (Spinacia oleracea), an annual plant, a member of the natural order Chenopodiaceae, which has been long cultivated for the sake of its succulent leaves. It is probably of Persian origin, being introduced into Europe about the 15th century. It should be grown on good ground, well worked and well manured; and for the summer crops abundant watering will be necessary.

The first sowing of winter spinach should be made early in August, and another towards the end of that month, in some sheltered but not shaded situation, in rows 18 in. apart &mdash; the plants, as they advance, being thinned, and the ground hoed. By the beginning of winter the outer leaves will have become fit for use, and if the weather is mild successive gatherings may be obtained up to the beginning of May. The prickly-seeded and the Flanders are the best for winter; and these should be thinned out early in the autumn to about 2 in. apart, and later

on to 6 in. The lettuce-leaved is a good succulent winter sort, but not quite so hardy. To afford a succession of summer spinach, the seeds should be sown about the middle of February, and again in March; after this period small quantities should be sown once a fortnight, as summer spinach lasts but a very short time. They are generally sown in shallow drills, between the lines of peas. If a plot of ground has to be wholly occupied, the rows should be about 1 ft. apart. The round-seeded is the best sort for summer use.

SPINAL CORD, in anatomy, that part of the central nervous system in man which lies in the spinal canal formed by the vertebrae, and reaches from the foramen magnum to the lower margin of the first lumbar vertebra. It is about 18 in. long, and only occupies the upper two-thirds of the spinal canal. The cord is protected by the same three membranes which surround the brain. Outside is the dura mater, which differs from that of the brain in not forming a periosteum not to the bones, in sending no processes inward, and in having no blood sinuses enclosed within its walls. In other words the spinal dura mater is the continuation of only the inner or cerebral layer of the dura mater of the skull. Inside the dura mater is the arachnoid, which is delicate and transparent, while between the two lies the sub-dural space, which reaches down to the second or third sacral vertebra. The pia mater is the innermost covering, and is closely applied to the surface of the cord into the substance of which it sends processes. Between it and the arachnoid is the sub-arachnoid space, which is much larger than the sub-dural and contains the cerebro-spinal fluid. Across this space, on each side of the cord, run a series of processes of the pia mater arranged like the teeth of a saw; by their apices they are attached to the dura mater, while their bases are continuous with the pia mater surrounding the cord. These ligaments, each consisting of twenty-one teeth, are the ligamenta denticulata, and by them the spinal cord is moored in the middle of the cerebro-spinal fluid. The spinal cord itself is a cylinder slightly flattened from before backward. In the cervical region it is enlarged where the nerves forming the brachial plexus come off, while opposite the lower thoracic vetebrae the lumbar enlargement marks the region whence the lumbo-sacral nerves are derived. (See fig. 2.) Opposite the second lumbar vertebra the cylindrical cord becomes pointed and forms the conus medullaris from the apex of which a glistening membranous thread runs down among the nerves which form the cauda equina, and after blending with the termination of the dural sheath, is attached to the back of the coccyx.

In a transverse section of the cord two median fissure are seen; the antero-median (see fig. 3, A) is wide, and reaches about a third of the way along the antero-posterior diameter of the cord; it is lined by the pia mater, which at its orifice, is thickend to form a