Brachycephaly

“ In regions where dolichocephaly (index less [Pg 11] than 80) abounds, the skulls of criminals show a very low index; if, on the contrary, they are natives of districts where brachycephaly (index 80 or more) prevails, they exhibit a very high index.
SKULL FORMATION
In 15.5% we find trochocephalous or abnormally round heads (index 91) . A very high percentage (nearly double that of normal individuals) have submicrocephalous or small skulls. In other cases the skull is excessively large (macrocephaly) or abnormally small and ill-shaped with a narrow, receding forehead (microcephaly, 0.2%) . ”

“ The relationship of the broad-headed race to other prehistoric and existing broad-headed races of western Europe is also a matter of very great interest. The Ofnet brachycephals are regarded by Schliz (13) as closely similar to the type skull of the so-called Grenelle race, which, in turn, is closely similar to the Furfooz type. Thus the cephalic index of one (Fig. 255) of these broad, flattened skulls of Ofnet is 83.33 per cent; the face is relatively narrow, the zygomatic index being low—76.34 per cent; the brain capacity of the female skulls does not exceed 1,320 c.cm. ”

“ In very many species, the beard, whiskers, and crests of hair round the face are of a different colour from the rest of the head, and when different, are always of a lighter tint, [45] being often pure white, sometimes bright yellow, or reddish. The whole face of the South American Brachyurus calvus is of a "glowing scarlet hue;" but this colour does not appear until the animal is nearly mature. [46] The naked skin of the face differs wonderfully in colour in the various species. It is often brown or flesh-colour, with parts perfectly white, and often as black as that of the most sooty negro. ”

“ From the nature of the sutures of the skull it is tolerably obvious that if brain capacity produces an enlargement of brain, the consequent internal pressure on the skull will be lateral and tend to produce brachycephalism. ”

“ In Discinisca and Lingula, however, the sub-oesophageal ganglion is not drawn out, but lies medianly; it gives off two posteriorly directed nerves to the stalk, which in Lingula unite and form a substantial nerve. Sense organs are unknown in the adult. The larval forms are provided with eye-spots, but no very specialized sense organs are found in the adult.
The histology of Brachiopods presents some peculiar and many primitive features. As a rule the cells are minute, and this has especially stood in the way of embryological research. ”

“ The first explanation, even granting that the brachycephalic races as a rule are endowed with a greater cranial capacity than the long-headed ones, could hardly be accorded a warm reception in any of the Anglo-Saxon countries like our own. ”

“ The digestive system of a brachiopod includes an œsophagus that leads into a simply formed stomach round which is a large digestive gland. The heart has only one cavity, but the animal is provided with two smaller and separate organs that assist in the propulsion of the blood, which circulates through numerous blood spaces in the bristly mantle.
About two thousand fossil species of brachiopods are known, extending over a vast range of time; and the living species, numbering less than a hundred, are found from shallow water to the greatest habitable depths. ”

“ Crania in life opens its valves by moving upon the straight hinge, without sliding the valve.
The nervous system of Brachiopods has, as a rule, maintained its primitive connexion with the external epithelium. In a few places it has sunk into the connective-tissue supporting layer beneath the ectoderm, but the chief centres still remain in the ectoderm, and the fibrils forming the nerves are for the most part at the base of the ectodermal cells. ”

“ Gosse's epithet "enormous." Whether this brain is highly organized enough to be a thinking apparatus, we do not know, but it is evidently the cause of a very vigorous and consentaneous action of the various organs the Brachion possesses.
A description of the Brachion would be very incomplete if it omitted that important organ the tail, which in this family reaches the highest point of development. It is a powerful muscular organ, of great size in proportion to the animal, capable of complete retraction within the carapace, and of being everted wholly, or partially, at will. ”

“ Such is the general arrangement of the shell muscles in the division composing the articulated Brachiopoda, making allowance for certain unimportant modifications observable in the animals composing the different families and genera thereof. Owing to the strong and tight interlocking of the valves by the means of curved teeth and sockets, many species of Brachiopoda could open their valves but slightly. In some species, such as Thecidea, the animal could raise its dorsal valve at right angles to the plane of the ventral one (fig. 4) . ”

“ The brachialis longus superior is a large nerve trunk which springs from most of the other plexus roots. It extends around to the dorsal side of the upper arm and supplies the skin, the feathers, and the muscles of the forearm and the hand. Branches from this nerve trunk supply the triceps brachii and other muscles of the region. The main branch passes between the radius and the ulna, and, passing the elbow-joint, gives off branches to that joint. ”

“ Brachycephalus ephippium in Brazil, the only species, is remarkable for the development of a broad dorsal shield of bone, which is fused with the processes of the second to seventh vertebrae, an ossification which strongly resembles that of several species of the likewise Brazilian Ceratophrys, a genus of the Cystignathinae. ”

“ The modified epithelium in connexion with the ganglia may possibly have some olfactory or tactile function, but beyond this the Brachiopoda would appear to be devoid of eyes, ears, or any other kind of sense organs,—a condition of things doubtless correlated with their sessile habits, and with the presence of a bivalved shell which leaves no part of their body exposed. ”

“ But this field is outside of the limitations of our Congress. It is easy at first sight to suppose a dolichocephalous skull to be transformed into a brachycephalous skull, but still nobody has ever observed the transformation of a dolichocephalous race into a brachycephalous one, or vice versa, or of a negro race into an Aryan race.
Prehistoric anthropology should find methods of facilitating acquaintance with the types of ancient races and peoples, and of making possible the discovery of them among living men. ”

“ We do not know what influences alter the shape of the skull, just as we do not know why people of British descent in the Darling region of Australia (“Cornstalks”) grow exceptionally tall, or why in New England their jaw-bones seem to become slighter and their teeth in consequence rather crowded. Even in Neolithic times dolichocephalic and brachycephalic skulls are found in the same group of remains and often buried together, and that is true of most peoples to-day. Some peoples, such as the mountain people of central Europe, have more brachycephalic individuals per cent. than others ”

“ The body cavity of a Brachiopod is traversed by several pairs of muscles, which are very constant in position, and whose contraction serves to open and close the shell, to move the animal upon its stalk, and to govern the movements of the arms. ”

“ Sub-Order 3. Brachyura. [147] The abdomen is much reduced, especially in the male, and is carried completely flexed on to the ventral face of the thorax so as to be invisible from the dorsal surface. The pleopods in the male are only present on the two anterior segments, and are highly modified as copulatory organs; the pleopods in the female are four in number and are used simply for carrying the eggs; the pleopods of the sixth pair are always absent in both sexes. The first antennae and the stalked eyes can be retracted into special pits excavated in the carapace.
182
Fig. ”

“ Numerous muscles exist which connect the valves of the shell to one another, and with the inclosed animal. And, though the visceral organization of the brachiopods is somewhat complex, no definite sense-organs have yet been detected in any of them. In the nervous system of these sedentary animals, there is, therefore, nothing answering to a brain as it is ordinarily constituted, though ganglia exist around the œsophagus which must receive afferent impressions of some kind, and from which branches proceed to the various muscles and viscera of the body. ”

“ In the meantime the second or mantle segment has grown down and enveloped the stalk, and four bundles of setae have [481] arisen from its edge. In this stage the larva leaves its mother’s shell and swims out into the world of water to look for a suitable place on which to settle down. This is the only stage in the life history of a Brachiopod when the animal is locomotor, and can serve to spread its species. The extreme minuteness of the larva and the short time it spends in this motile condition probably accounts for the fact that Brachiopods are extremely localised. ”

“ The soft parts are composed of muscles, the mantle (which secretes the valves) , digestive, respiration, reproductive, and excretory organs, and the tentacle-bearing lophophore.
In adult life the brachiopod is attached to the sea bottom by means of a fleshy stalk called the pedicle (fig. 14) , and this is usually extruded through a hole (the pedicle foramen) which is located in the ventral or pedicle valve. The upturned area which is usually present on the pedicle valve is called the beak. ”

“ The ancient British brachycephalic skull from Ballidon Moor, described by Davis, [20] has large frontal sinuses, prominent supraorbital ridges, and well-developed muscular impressions on the facial bones. The prominence of the orbital border is less considerable in the ancient British skull, which is also brachycephalic, described by Retzius. An ancient rounded Irish skull also exhibits large supraorbital ridges projecting in front of the frontal bone, and meeting in the middle, and a depressed forehead. ”

“ Heads still all brachycephalic and of only moderate height; faces broad, noses not prominent, in males tend to large.
Two adult men, evidently full-bloods—pure Indian type of the brachycephalic form, head moderate in size, medium short, face not very large, nose slightly or moderately convex, not prominent, but all Indian. Color of skin submedium to near medium brown, no trace of whitish or pink. Stature and build medium; feet rather small; hair typical Indian, black, straight; beard sparse and short; mustache sparse, no hair on sides of the face. ”

“ Thus, in order to give a few examples, the powerful chelæ of the antepenultimate pair of feet, of Phromina sedentaria, are produced, according to Pagenstecher, from simple feet of ordinary structure; and vice versà, the chelæ on the penultimate pair of feet of the young Brachyscelus, become converted into simple feet. In the young of the last-mentioned genus the long head is drawn out into a conical point and bears remarkably small eyes; in course of growth, the latter, as in most of the Hyperinæ, attain an enormous size, and almost entirely occupy the head, which then appears spherical, etc. ”

“ Head form is most conveniently expressed by means of the cephalic index, that is, the ratio of breadth to length. Anthropologists generally speak of any one with an index of 75 (or where the breadth is 75% of the length) and below this as dolichocephalic, or long-headed; from 75 to 80 is the class of the mesocephalic, intermediates; while above 80 is that of the subbrachycephalic and brachycephalic, or round-headed. For the most part, the Old Americans fall into the intermediate class, the average index of males being 78.3 and that of females 79.5. ”

“ Fossil examples of this group occur in Australia both in Palaeozoic rocks and, more numerously, in the Cainozoic series.
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MOLLUSCOIDEA.—The Brachiopods or Lamp-shells consist generally of two calcareous valves as in the true mollusca (Fig. 23) , but are sometimes of horny texture. Like the previous class, they are also easily preserved as fossils. They possess bent, loop-like or spiral arms, called brachia, and by the movement of fine ciliated (hair-like) processes on their outer edges conduct small food particles to the mouth. ”

“ The following six genera are placed by Lamarck in this family:—Sphærulites, Radiolites, Calceola, Birostrites, Discina, Crania. Of these, Calceola, Discina, and Crania are shewn to belong to the Brachiopoda.
7. Brachiopoda (plates, fig. 201 to 219) . The shells of this family are inequivalve, equilateral, and attached to marine bodies by a tendon passing through one of the valves. The animals have, near their mouth, two elongated, ciliated arms, which are spirally rolled when at rest. The following genera are enumerated by Lamarck, Orbicula, Terebratula, Lingula. ”

“ Brachysceles may readily be met with among the labouring classes, habituated from childhood to hard toil in a standing position, thus interfering with a free development of the long bones of the lower limbs; while the macroscelous type will be found among the [Pg 80] aristocratic classes, whose members, spending much time sitting or reclining, give the long bones an opportunity to attain their growth (mechanical theories of stature) . ”

“ Unfortunately almost every anatomist who has written on the muscles of the Brachiopoda has proposed different names for each muscle, and the confusion thence arising is much to be regretted. In the Testicardines, of which the genus Terebratula may be taken as an example, five or six pairs of muscles are stated by A. Hancock, Gratiolet and others to be connected with the opening and closing of the valves, or with their attachment to or movements upon the peduncle. ”

“ In Megerlia it is three times attached, first to the hinge-plate, and then to the septum by processes from the diverging and reflected positions of the loop. In Magas the brachial skeleton is composed of an elevated longitudinal septum reaching from one valve to the other, to which are affixed two pairs of calcareous lamellae, the lower ones riband-shaped; attached first to the hinge-plate, they afterwards proceed by a gentle curve near to the anterior portion of the septum, to the sides of which they are affixed ”