Phillida

“ It is capable of wandering at will from one eye to the other, to disappear into the deeper parts of the orbit, to wander under the skin of the eyelids, and even to make excursions in the temporal region. These seem to be the limits of its excursions. No doubt the Rev. Dr. Nassau (the missionary at the Gaboon) had sometimes sensations of a filaria under the skin of the fingers as well as under the skin of the eyelid, but it is doubtful if this was a true case of Filaria loa, and even then if the worm had made its way from the fingers to the eyelid. ”

“ Manson, who writes the article on filaria, reports the case of a negro who had been affected with Filaria loa, and in whose blood he afterwards found the Filaria diurna, and raises the question whether the Filaria loa may not turn out to be the female parental form of the Filaria diurna.
I am afraid we must confess that we are as yet very ignorant of many points connected with the life history of the Filaria loa. With the adult female parasite we have a limited acquaintance, but till now we are ignorant of the appearance of the male worm. ”

“ Ten years later Manson discovered a second species, Filaria perstans, whose larvae live in the blood. They, however, show no periodicity, and are found continuously both by day and by night; and their larval forms are termed Microfilaria perstans. The adult stages are found in the sub-peritoneal connective tissue. A third form, Microfilaria diurna, is found in the larval stage in blood, but only in the daytime. The adult stage of this form is the Filaria loa found in the subcutaneous tissues of the limbs. ”

“ This opinion appeared to me to be strengthened by the fact that this patient had previously had a loa under the conjunctiva. I have very little doubt that the embryo of Filaria loa finds its way into the blood. Clinically, there is no evidence of its attempting to find its way to the surface of the body, and it is evident that there must be some arrangement by which it can get out of the body, and so propagate its species by passing from one person to another. ”

“ Two or three years ago I had an opportunity of examining the blood of a number of negroes from Old Calabar in a missionary establishment and elsewhere, and I made the interesting discovery that in 50 per cent. the blood contained the embryos of a species of filaria—Filaria perstans—which were quite different in their zoological characters from the filaria of the blood, with which every one must now be familiar. ”

“ As we drew near the town, I could see some of the young fellows we met cast admiring looks on Phillis; and that made me look too. She had on a white gown, and a short black silk cloak, according to the fashion of the day. A straw bonnet with brown ribbon strings; that was all. But what her dress wanted in colour, her sweet bonny face had. The walk made her cheeks bloom like the rose; the very whites of her eyes had a blue tinge in them, and her dark eyelashes brought out the depth of the blue eyes themselves. ”

“ As regards her general appearance, the female Filaria loa resembles the male parasite, only she is considerably larger and her tail is straight, tapers to a diameter of about 0·1 mm., and is then abruptly truncated. The mouth, the head, the stout muscular ring just posterior to the mouth, the stout longitudinal muscular bands, and the bosses on the integument resemble exactly those of the male worm. In consequence of the mutilation of the specimen it is impossible to say where the vagina opens, or where the anus is placed. ”

“ When as her leaves great moan for pity maken.
The falling fountains from the mountains falling,
Cried out, alas, so fair and be so cruel!
And babbling echo never ceasèd calling,
Phillis, disdain is fit for none but truthless.
The rising pines wherein I had engraved
Thy memory consulting with the wind,
Are trucemen to thy heart and thoughts depraved,
And say, thy kind should not be so unkind.
But, out alas! so fell is Phillis fearless,
That she hath made her Damon well nigh tearless. ”

“ Filaria loa: male.—Body filiform, cylindrical, measuring from 25 mm. to 30 mm. in length, by 0·30 mm. in breadth, of uniform thickness, except where it tapers at the head and tail. The cephalic end tapers somewhat abruptly to the simple mouth, which is destitute of papillæ and armature. There is no distinctly marked [6] neck, but there is a sort of shoulder about 0·15 mm. behind the mouth, where a number of strong muscular longitudinal bands originate to pass down the body. In one of the specimens the extreme head end is retracted and abruptly truncated, measuring at the free end 0·1 mm. ”

“ Four years later Bancroft, in Brisbane (Queensland) , discovered the adult form, and Cobbold named it Filaria bancrofti. Since that time the subject has rapidly expanded, and its great practical importance in tropical pathology is now recognized.
Nomenclature of the parasites.— I have pointed out that Lewis's microfilaria* [1] is not the only blood-worm in man, and that the human circulation is the habitat of the larvae of no fewer than five, possibly of six or even more, distinct species of filariæ. ”

“ The Filaria immitis is a species found by [Pg 154] Mons. Krabbe in a dog which died of a disease to which these animals are subject; it lived in the heart, and twelve individuals, ten females and two males, were found to be lodged there. Mons. Bap. Molin has published a monograph on the Filariæ, giving the characters of 152 species met with in molluscs, fishes, amphibians, reptiles, birds, and mammals: it seems evident that many species have been confounded under the same name. ”

“ There would be a discharge of the embryos into the water, and if less care were taken about the purity of the water-supply, and supposing there to be no adverse climatic influences, the worm would become common. This little story about guinea-worms shows how these and similar parasites pass from one man to another; and it shows how slight differences of habit, absence of intermediate host, and so on, govern the distribution of a parasite like Filaria loa. ”

“ Twisted round the worm, and apparently attached to it near its centre, was a much finer, less firm, transparent filamentous body, which I at first thought might possibly prove to be a second young filaria, or even the male filaria, but which on further careful microscopical examination appears to be the alimentary canal of the worm protruded through an opening in its musculo-cutaneous wall, caused by the forcible grasping of the parasite with the forceps. ”

“ Fig. 112—Tsetse-fly. (After Manson.)
[Pg 165]
This species, Filaria bancrofti, is not only very widely distributed, but in regions such as some of the South Sea Islands a very large per cent of the natives have the filariæ present in their blood. When these parasites are withdrawn from the circulation and placed on a slide for study they are seen to be minute transparent, colorless, snake-like organisms inclosed in a very delicate sack or sheath. They are but a little more than one-hundredth of an inch long and about as big around as a red blood-corpuscle. ”

“ I went up to her. “Oh, Phillis! I am so sorry—I thought you would, perhaps, have cared to hear it; he did talk so feelingly, as if he did love you so much, and somehow I thought it would give you pleasure.”
She lifted up her head and looked at me. Such a look! Her eyes, glittering with tears as they were, expressed an almost heavenly happiness; her tender mouth was curved with rapture—her colour vivid and blushing; but as if she was afraid her face expressed too much, more than the thankfulness to me she was essaying to speak, she hid it again almost immediately. ”

“ The Sphaeridiides are in large part terrestrial, but their separation from the purely aquatic Hydrophilides cannot be maintained on any grounds yet pointed out. Altogether about 1000 species of Hydrophilidae are known, but this probably is not a tenth part of those existing. In Britain we have nearly ninety species. Some taxonomists treat the family as a series with the name Palpicornia. The series Philhydrida of older authors included these Insects and the Parnidae and Heteroceridae. ”

“ Phillis was carried down-stairs, and lay for hour after hour quite silent on the great sofa, drawn up under the windows of the house-place. She seemed always the same, gentle, quiet, and sad. Her energy did not return with her bodily strength. It was sometimes pitiful to see her parents’ vain endeavours to rouse her to interest. One day the minister brought her a set of blue ribbons, reminding her with a tender smile of a former conversation in which she had owned to a love of such feminine vanities. ”

“ The filarial worms are thread-like nematodes, with a thin cylindrical oesophagus, which live in various parts of the body and may or may not give rise to disease conditions. It is one of the most remarkable facts in animal parasitology that a person may harbor numerous adult filariae and myriads of embryos without in any way manifesting symptoms of the infection. In most of the filarial worms the female has a double uterus with the uterine opening near the anterior extremity. ”

“ I do not suppose that in all her life Phillis had ever shown so much temper before. In many a family the tone, the manner, would not have been noticed; but here it fell with a sharp surprise upon the sweet, calm atmosphere of home. The minister put down ruler and book, and pushed his spectacles up to his forehead. The mother looked distressed for a moment, and then smoothed her features and said in an explanatory tone,—“It’s the weather, I think. Some people feel it different to others. It always brings on a headache with me.” ”

“ Abdomen small terminating in a blunt point, and in the female provided with a distinct borer. The feet are short and robust, and the head is of a light green color.
The Psylla counts two generations which succeed each other in the spring, during the evolution of the blossoms. At the commencement of the warm season some of the insects die, while others of both sexes remain through the summer. During the autumn and winter they seek shelter on the under part of the leaves, or stalks of the tender shoots, and shield themselves there as best they may from the storms. ”

“ History.— Our knowledge of this subject dates from the discovery by Demarquay, in 1863, of a larval nematode— microfilaria bancrofti (Plate X.) —in the milky fluid from a case of chylous dropsy of the tunica vaginalis. Later, in 1866, Wiicherer found the same organism in the urine of a number of cases of chyluria. In 1870 Lewis made a similar observation in India, and in 1872 discovered that the blood of man was the normal habitat of this larval parasite, which he named, accordingly, Filaria sanguinis hominis. ”

“ Both the chyluria and the presence of filariae in the blood are curiously intermittent; it may happen that not a single filaria is to be seen during the daytime, while they swarm in the blood at night, and it has been ingeniously shown by Dr S. Mackenzie that they may be made to disappear if the patient sits up all night, reappearing while he sleeps through the day. ”

“ The third species, P. asterius, has a more southerly distribution. Its female is darker and nearer to philenor than the male. It must, however, be admitted that none of the three species bears a very close resemblance to philenor. It is suggested that this is because P. philenor is a tropical form which has only recently invaded N. America. The crossing of philenor has, as it were, induced the three mimicking Papilios to turn dark, but the model has not been long enough in contact with them for the likeness to become a close one. ”

“ This, however, might happen in Philoscia, in which the larval skin is closely applied to the egg-membrane (Fig. 38) , and is only to be explained as the larval skin by a reference to Ligia and Cassidina. The foliaceous appendage on the back has long been known in the young of the common Water Slater (Asellus) . [1] That the last pair of feet of the thorax is wanting in the young of the Wood-lice (Porcellionides, M.-Edw.) and Fish-lice (Cymothoadiens, M.-Edw.) has already been noticed by Milne-Edwards. ”

“ Filoplumes are degenerate structures having a superficial resemblance to hairs, but they always bear a minute vane at the tip. They occur in all birds, in clusters of varying number, about the bases of contour feathers. In some birds they attain a great length, and may project beyond the contour feathers, sometimes forming conspicuous white patches, as for example in the necks of cormorants. In their early stages of development they often possess a large aftershaft made up of a number of barbs, but these quickly disappear, leaving only the degenerate main shaft. ”

“ The larger bosses are found towards the middle of the parasite; at the head and tail they are considerably smaller, and in these situations they are more sparingly distributed. The larger measure at the base 0·12 mm., and rise about 0·004 mm. above the general surface. The extreme ends of the parasite are not provided with bosses, the first met with being about 1·5 mm. ”

“ Filberts, specially exposed to the attacks of the cunning dormouse and the persistent nut-hatch, are far more effectually guarded by a double coat-of-mail: their shell is solid and woody in texture, while their outer husk, which completely envelops them from stem to tip, is thickly sprinkled with stiff and annoying hairs, very painful to our human fingers, and still more so, no doubt, to the tender skin on the naked noses of the inquiring rodents. ”

“ He did not notice that the worm was influenced in its visits by the external temperature.
In addition to these cases among members of the Old Calabar Mission, I may refer to the experience of Dr. Thompstone, who was for eighteen months stationed at Opobo, on the delta of the Niger, and who is in this country at present. He informs me that while he was at Opobo he saw two cases of Filaria loa. In the one negro the parasite was situated in the lower eyelid at the inner canthus close to the lachrymal sac—the swelling in that region giving the appearance of dacryocystitis. ”