Frenulum

“ Hampson says "the form of the frenulum is of great use in determining sex, as in the males of all the forms that possess it, it consists of hairs firmly soldered together so as to form a single bristle, whilst in nearly all females it consists of three or more bristles which are shorter than that of the male; in one female Cossid I have found as many as nine. Also in the large majority of moths the retinaculum descends from the costal nervure in the male, while in the female it ascends from the median nervure." ”

“ The North American Megathymidae and the Australian Euschemonidae have a frenulum and are usually reckoned among the “moths.” The Hesperiidae in which the frenulum is wanting form the large family of the skipper butterflies, represented in our own fauna by several species. They are insects with broad head—the feelers being widely separated—usually brown or grey wings (fig. 50) and a peculiar jerky flight. The family has an extensive range but is unknown in Greenland, New Zealand, and in many oceanic islands. ”

“ Similarly knobbed antennae occurring in the higher Caradrinina (Agaristidæ) have been thought to indicate relationship to the Papilionina; but there the frenulum is always strong and persistent, and the required simple type of neuration is never found. Hence we must suppose that the Thyrididæ are the true starting-point of the group. ”

“ In butterflies there is no frenulum, but a costal outgrowth of the hindwing subserves the same function. In the most primitive moths a small lobate outgrowth—the jugum (fig. 6, j.) —from the dorsum of the forewing is present, but it can be of little service in keeping the two wings together. A jugum may be also present on the hindwing. The legs, which are generally used for clinging rather than for walking, have five-segmented feet and are covered with scales. ”

“ This group includes a number of moths of delicate build with elongate legs, the maxillae and their palps being usually well developed. The forewings have two anal nervures, the hindwings three (fig. 30, h, i) ; in the hindwing the sub-costal nervure bends towards and often connects with the radial, and the frenulum is usually present. The egg is flat. The larva has complete circles of hooklets on its five pairs of prolegs, and the pupa (usually completely obtect) does not move at all from its cocoon. This group includes the only Lepidoptera that have aquatic larvae. ”

“ This is the system found in butterflies and in some of the large moths, such as Lasiocampidae and Saturniidae; in these cases the hind {316}wing always has a large shoulder, or area, anterior to its point of insertion. In most moths this shoulder is absent, but in its place there are one or more stiff bristles projecting forwards and outwards, and passing under a little membranous flap, or a tuft of thick scales on the under face of the front wing; the bristle is called the "frenulum," the structure that retains it a "retinaculum." ”

“ Noctuidae (Owlet-Moths, Eulen of the Germans) .—This very extensive assemblage consists of moths rarely seen in the day-time, of generally sombre colours, with antennae destitute of remarkable developments in the male (except in a small number of forms) ; proboscis and frenulum both present; a complex sense-organ on each side of the body at the junction of the metathorax and abdomen. The number of species already known can scarcely be less than 8000; owing to their large numbers and the great general resemblance of the forms, their classification is a matter of considerable difficulty. ”

“ The use of this frenum is to confine the movements of the prepuce, and to draw down the mouth of the water passage to direct the flow of the urine. Sometimes the frenum is too short, and confines the prepuce too much; it may be slit down with a pair of scissors as far as is considered expedient. The frenum is frequently ruptured in a first coition. The frenum is very elastic, and protects the sensitive surface beneath it as the eyelid does the eye. Sometimes, however, it becomes permanently contracted;—the glans is then denuded, but soon loses its sensibility. ”

“ The power of originating contractions evidently resides in the velarium or in the ganglion cells of the frenula just as it does in the proboscis and the floor of the stomach.
Small pieces cut from between the pedalium corners and the frenula, so as to have tissue on them from neither, could contract by themselves. (See also for Pedalia, Experiments 15, 23, 41b; Velarium 18, 41c.)
Tentacles.—31. A cut-off tentacle can contract by itself, sometimes with squirming contractions. A prick at either end can produce a forcible contraction. ”

“ Now I think no one will dispute that the ovigerous frena in the one family are strictly homologous with the branchiæ of the other family; indeed, they graduate into each other. Therefore it need not be doubted that the two little folds of skin, which originally served as ovigerous frena, but which, likewise, very slightly aided in the act of respiration, have been gradually converted by natural selection into branchiæ, simply through an increase in their size and the obliteration of their adhesive glands. ”

“ The cartilaginous combs, or fringes, attached to the concave borders of the branchial arches, are set in two rows on each arch; these two rows are likewise divergent, so that the tips of the fringes of the outside row of one arch, meet the tips of the fringes of the inside row of the next one. The tips of each pair of fringes firmly coalesce and cannot be separated without breaking them. ”

“ Fernelius proves that there are animal spirits, by saying that the cells in the brain are apparently unoccupied, and as nature abhors a vacuum, he concludes that in the living body they are filled with spirits, just as Erasistratus had held that, because the arteries were empty of blood, therefore they must be filled with spirits. But Medical Schools admit three kinds of spirits: the natural spirits flowing through the veins, the vital spirits through the arteries, and the animal spirits through the nerves ”

“ When we conceive the phronema as the real "organ of the soul" in the strict sense—that is to say, as the central instrument of thought, knowledge, reason, and consciousness—we may at once lay down the principle that there is an anatomical unity of organ corresponding to the physiological and generally admitted unity of thought and consciousness. As we assign to this phronema a most elaborate anatomical structure, we may call it the organic apparatus of the soul, in the same sense in which we conceive the eye as a purposively arranged apparatus of vision. ”

“ Comparison.—No significant differences noted among the species studied.
Musculus obturator internus (Figs. 4, 7) .—Lying on the inside of the pelvis and covering the medial surface of the ischiopubic fenestra, is this flat, pinnate, leaf-shaped muscle. The origin is fleshy and is from the ischium and pubis around the edges of this fenestra; none of the fibers arises from the membrane stretched across the fenestra. Anteriorly the fibers converge and form a strong tendon that passes through the obturator foramen and inserts on the posterolateral surface of the trochanter of the femur. ”

“ In the Alloeocoela and Tricladida the pharynx is an elongate protrusible cylinder, and in the Polyclads it may be an immensely distensible frilled organ, the folds of which have independent movement, or an elongate tube. At the base of the pharynx lie the openings of salivary glands. In the Polycladida the section of the alimentary sac into which the pharynx opens is a median stomach from which the intestinal branches radiate. The stomach in few forms is provided with digestive glands. The branches possess an independent musculature and exhibit active peristalsis. ”

“ Female (based on three adults) : See measurements and plates 34-36. As described in Mustela frenata frenata except that: Weight, 3.1 (2.6-3.5) grams; basilar length, 42.7 (40.8-45.5) ; zygomatic breadth less than distance between condylar foramen and M1 and more or less than distance between anterior palatine foramen and anterior margin of tympanic bulla.
The skull of the female averages 50 per cent lighter than that of the male. ”

“ As will be seen in Fig. 31, each of the endoderm cells of the tentacles has a flagellum that extends into the lumen of the tentacle. Each flagellum has a thickening just within its cell, which may be regarded as a basal body. From this basal body, again, a small fiber extends centrad into each cell. It does not appear that the flagella are thrown off with the distal parts of the cells ”

“ Not merely, however, are the difficulties of phrenology limited to the lower animals. Suppose we make a cross-section of a human skull through either the right or left side of the forehead, about half an inch above the upper border of the orbit or eye cavity. We may then discover that man as well as the elephant possesses "frontal sinuses" or air-spaces in his forehead-bone of considerable extent intervening between the exterior of the skull and the contained brain. Now, in such a section of the human skull, what phrenological "organs" shall we cut through? ”

“ The suspensoria are much more developed than in Charybdea, so that the interradial funnels lying between are more marked. In a corresponding way the frenula are larger and stouter (Figs. 28, 29, frn) . The musculature shows no new features and differs only in being comparatively more strongly developed and having a more pronounced striation. The nerve ring follows the same looped course from the margin in each interradius up to the level of the sensory clubs in the perradius. ”

“ The excreting spinnerets are almost all at the edge of the body, and the fringe is formed of feather-like segments, each segment corresponding to a spine.
Test of male white, thick, felted, oval, and convex; length, about 1/16in. Fringe as in the female.
Adult female dark-brown, sometimes almost black; slightly elongated, convex, affecting almost altogether the twigs and branches in preference to the leaves. Average length, about 1/9in. Antennæ of seven joints: on the last joint some hairs. Feet with the tibia about half as long as the tarsus (see note above, under the genus) . ”

“ What had before seemed a sluggish inert body, now, as in a former case, became instantly endowed with spasmodic life, leaping from the stones, twisting, twining, knotting itself, and then unfolding and reknotting itself in the most extraordinary manner, the grey rocks around being spattered with the blood from the bleeding neck, while the severed head lay slowly gasping, and biting impotently at a few dry blades of grass. ”

“ From the new stand-point of evolution through natural selection the facts in Sprengel's work took on a most important significance. Darwin now reaffirmed the Sprengel theory so far as the necessity of the insect was concerned, but showed that all those perplexing floral conditions which had disproved Sprengel's assumption, instead of having for their object the conveying of pollen to the stigma of the same flower, implied its transfer to the stigma of another, cross-fertilization being the evident design, or evolved and perpetuated advantage. ”

“ Internally, behind the mouth, there is a strong pharynx, shown in the accompanying diagram (Fig. 1) which is pushed forwards when the animal eats, and this part corresponds, according to Perrier, with the protrudable trunk or proboscis of other annelids. The pharynx leads into the œsophagus, on each side of which in the lower part there are three pairs of large glands, which secrete a surprising amount of carbonate of lime. These calciferous glands are highly remarkable, for nothing like them is known in any other animal. ”

“ In the intervening space a large glassy hernia rises and disappears, disappears and rises. When the two halves move asunder, with one eye forced back to the right and the other to the left, it is as though the insect were splitting its brain-pan in order to expel the contents. ”

“ It has the same comparative massiveness of forehead, not receding like the Celtic—the same even roundness in the frontal organs; but it is far loftier in the apex, and far less pronounced in the hinder cranial hemisphere where phrenologists place the animal organs. To speak as a phrenologist, the cranium common to the Vril-ya has the organs of weight, number, tune, form, order, causality, very largely developed; that of construction much more pronounced than that of ideality. Those which are called the moral organs, such as conscientiousness and benevolence, are amazingly full ”

“ The body of the sphenoid is impressed on its cranial surface with a broad and shallow sella turcica (a) , bounded by two grooves, (b b,) leading forwards and inwards from the carotid foramina (c) ; the line of suture between the sphenoid and occipital bones runs along a slight transverse elevation (d) , which bounds the sella posteriorly; this suture is partially obliterated: a slight median protuberance (e) bounds the sella turcica anteriorly; there are neither anterior nor posterior clinoid processes. External to the carotid channel there is a wide groove (f) leading to the foramen ovale (g) ”

“ In the western subspecies of M. frenata, and in its tropical subspecies, animals so young as to have pointed tails commonly have the underparts of the body more intensely colored than do adults. The young may have salmon-colored instead of yellowish fur on the underparts. ”

“ In one species of the genus the frond is completely covered with cortex cells, and at each node of the frond there is a single spine which, although so small as to be invisible without a lens, so effectually locks the threads together that they form an entangled mass that is not easily arranged to the satisfaction of the collector. ”