Hilderic Friend

“ A good deal of material is needed within the egg in order that a perfectly developed brood may emerge, and when the parent is compelled, through the struggle for existence, to launch a bevy of young on the sea of life, it cannot possibly fill the pockets of each (to speak metaphorically) with the almighty dollar, or provide that its offspring shall be started in life as are the progeny of individuals whose dangers are fewer and whose resources are more abundant. ”

“ When two worms are about to form an egg-case it is necessary that they should work in unison. One worm cannot do the work alone, though each worm is at the same time both male and female or hermaphrodite. A pair therefore approach each other from opposite directions, each having its head towards the other's tail. Near the middle of each adult worm is a swollen portion called the girdle or clitellum. This peculiar organ yields the horny substance of which the egg-case is formed, but it is at first soft and pliable, hardening after exposure to the air and cold. ”

“ The dorsal pores are never developed upon the first one or two segments of the body, and the point where they commence is characteristic for the species. The dorsal pores were considered at one time to lead into sacs, the function of which was believed to be respiratory; it is now known that the pores are simply perforations of the integumental layers just at the anterior boundary of the segment to which they belong; there is no lining of epithelium, as has been erroneously stated to be the case; there is simply a discontinuity of the muscular and epidermic layers where the pores exist. ”

“ The egg of the Earthworm is seldom more than a quarter of an inch in length, and, as it is usually oval, the shortest diameter is only about half that length. It was long ago pointed out that eggs almost invariably remain during the hatching period the same size as they were when first extruded, but here is a curious exception to the rule. We should look with amazement on a Pigeon's egg which increased in size till it became as large as a hen's egg during the time when the mother bird was sitting upon it, but this is exactly what happens in the egg before us during the hatching period. ”

“ Now it follows that if a number of species of worms lived together in one place, as they usually do in a manure-heap, it would be a great advantage for a given species to possess a distinguishing feature, such as that of luminosity, to enable two individuals to discover each other's whereabouts, just as the male Glowworm detects the female by the light emitted from her upturned abdomen. ”

“ The embryology of the worm has been fully studied, and is replete with marvels. If an egg is examined when the young embryo is almost ready to emerge, it will be possible, through the semitransparent and greatly dilated case, to watch the movements of the worm, trace the current of blood along the elaborate system of vessels, and eventually observe the emergence of the baby Annelid into the world. ”

“ Nearly every time I go out to collect, some species new to Britain or to science is discovered; and, as each species has its place in the economy of nature, it is clear that we have much yet to learn respecting the part which the lesser worms play as friends or foes of the farmer and the gardener. ”

“ If the eggs of a bird or fowl be varnished so as to exclude the air, or if they are enclosed in vessels, or buried in soil at a considerable depth, the young will never be hatched; yet here is an egg which can only be hatched when it is kept moist and cool, and one which may be buried at a depth of some inches, or even feet, in earth or under water, and yet retain its vitality. ”

“ The philosopher no sooner learns a new fact than he begins to pry into the secret which lies beneath, and stands to it as cause to effect. We have analogy to guide us. The water worms may be compared with the marine animals which produce phosphorescence, while the Brandling may be studied in the light of a Glowworm. It may be objected that as worms, except in a few rare cases, have no eyes there can be no advantage in their luminosity. ”

“ All day long they remain hidden close to the earth, but at the appointed hour of evening they will mount the blades of grass as high as they will bear them, turn up the ends of their tails, and display a splendour more steady and beautiful than either gas or camphine. ”

“ Darwin remarks that as worms are destitute of eyes he at first thought that they were quite insensible to light. He found, however, that "light affects worms by its intensity and by its duration." Hoffmeister states that, with the exception of a few individuals, worms are extremely sensitive to light, and from my own observations I have been able to demonstrate that there are marked differences in the susceptibility of the different species—some being very much more susceptible than others. ”

“ Slight chemical changes produce greater or lesser degrees of hardness in the substance. Hence horny substances are not all alike hard, and the horny capsule of the worm is tolerably elastic; so that when kept in a moist condition it can be slightly expanded by the internal pressure exerted by the growing worm. But how can the worm grow? The chick can become no larger than the shell-surrounded yolk and albumen will permit, but when the young worm is hatched it will very probably be an inch in length. ”

“ So far as I have been able to find during a long and extensive period of study, Swammerdam, who wrote the ' Book of Nature,' is almost the only observer who has devoted any attention to the systematic study of these eggs; but the result of his researches was such that he writes:—"Among all the eggs of insects, of which I have various species in my collection, I know none worthy of greater attention." ”

“ According to Breese the luminosity exists in the excreted glutinous material with which the outer skin of the animal is covered. It is much to be regretted that (so far as I can learn) the researches of this naturalist have never been given to the public in detail.
More than one creature has at different times borne the name of the phosphorescent worm. In 1837 Dugès, a French writer, described a species under this name (Lumbricus phosphoreus) with a girdle extending from the 13th to the 16th segments, and a somewhat flattened body behind. ”

“ We usually think of eggs as consisting of a yolk surrounded by albumen, and enclosed in a hard shell made of lime or some form of calcium. The eggs of birds and fowls are our types, but the egg of the Earthworm has no chalk-like shell. ”

“ I have named the species magna, because it is by far the largest yet described. I have not studied the nephridia, nor have I as yet determined the salivary glands, for want of material. The worm, which is sluggish in its habits, is found in moist places by slowly moving water. I found the same worm, or a close ally, at Hastings last summer, but, as only one specimen was taken, and one's holiday equipment does not render identications easy, the exact species was not determined. ”

“ A light flashed out in time of danger would scare a would-be intruder, which would soon become used to a regular light and learn its innocuousness. If, as Pietro Martire tells us, the people of the West Indies were alarmed when they met a fellow in the dark whose face had been smeared with the phosphorescence of an insect, it is not unreasonable to suppose that a Trout would be alarmed if a Brandling suddenly lighted its lamp. Further observation on this subject is greatly to be desired. ”

“ Viewed in this light, a new field of research is opened up which hitherto has been totally unworked, but which may be hoped to yield remarkable results if diligently, patiently, and intelligently tilled. ”

“ The naturalist is already well aware of the fact that when an animal regularly lays a large quantity of eggs of minute dimensions, the offspring is almost invariably unlike its parent, and has to undergo sundry transformations, changes, and developments before arriving at any degree of perfect resemblance to the adult form. ”

“ There is no doubt but that many of our minute annelids are parasitic. Heretofore, however, we have heard little of their ravages. The reason is probably to be found in the fact that so little was known formerly of annelid anatomy that when a worm was discovered its description lacked scientific precision, and so the different parasitic worms remained uncatalogued and unknown. ”

“ In one specimen the four posterior segments were without setæ, and the penultimate set of four had only one seta in each sac. A marked peculiarity of this species is to be found in the colour of the blood, which is decidedly disposed to be red, as may be seen when the worm has been kept for a day or two in clean water. The body segments are striate, with about half a dozen rows of striate cells per segment. The girdle extends over segment xii and the hinder half of segment xi, the usual glandpores being found on the former segment. ”

“ While few records of a reliable nature respecting the observation of luminous worms in Britain are available, a good deal has been done by our continental fellow-workers. Vejdovsky, who wrote a very valuable work on the various species of annelids in 1884, entitled 'System und Morphologie der Oligochæten,' gives us some results of his personal experience, which I believe have never been placed before the English reader. He says that he had the good fortune once to observe an interesting case of phosphorescence in connection with the Brandling. ”

“ It has been correctly surmised that the number of eggs laid by a bird or other animal bears a close relation to the exigencies and dangers which the young will be likely to encounter. Hence a Pigeon lays only a single pair of eggs for each brood, while the Thrush deposits some half-dozen in its nest ”

“ L. wordsworthianus, Friend.—A species new to science found by myself in a pond at Old Carlisle, Wigton, Cumberland. It lives in mud at roots of plants, and when taken coils up as Tubifex does. When examined under the microscope the absence of capilliform setæ at once shows it is not Tubifex, while the fact that it has more than two setæ in each anterior bundle differentiates it from Stylodrilus, a worm which is moreover readily distinguished by its appendant penis. The worm is from two to three inches long, but owing to its habit of coiling up is very difficult to measure. ”

“ It seems somewhat curious that an egg possessing so many peculiarities should have been almost absolutely ignored by scientific men and naturalists generally, the more so as it is easily obtained and readily examined. ”

“ One investigator at least has tested the colour and composition of the luminosity by the spectroscope, and says that it is not unicolored or monochromatic, but compounded chiefly of the red and violet rays. Other students regard the substance which produces the light as homogeneous. ”

“ Thus we see that even now, notwithstanding the large amount of attention which has been paid to Earthworms during the past decade, we are very badly informed on many points connected with their economy; and there is great need that some one, with the necessary leisure, means, and scientific training, should investigate some of the details more fully. ”

“ There are no swellings or off-growths on the nerve-ganglion, which is of practically equal size throughout. The salivary glands are unbranched and club-shaped, being swollen or knob-like at the free extremity. The spermathecæ open in the usual place between segments iv-v, without glands, while the internal extremity is somewhat pear-shaped, and without diverticula or sac-like appendages. The girdle is minutely papillose, or presents a fine granular appearance. Very long coiled tube extending back to segment xx, or even as far as xxiv. The first nephridium seemed to lie in segment vii. ”

“ Until we know more of the limits and extent of variation, and can draw a firmer line between species and subspecies, form and variety, it is better not to multiply terms. Several subspecies and varieties have been named by Rosa, Ribaucourt, and others, and our British forms would well repay careful examination. ”

“ J. Wighton on insect luminosity, seeing that many cases of phosphorescence attributed to worms really come under this head. He says:—
"The Centipede (Scolopendra electrica, L.) is one of the few luminous insects met with in this country. Its specific name electrica seems to be a misnomer; lucifera or phosphorifera would be more applicable. It would take a large number of Centipedes to give a sensible shock, even supposing the creature capable of doing so at all. In other electric animals, as the Torpedo, no flash appears, even when they give a discharge strong enough to stun a horse ”

“ In the living worm the brain appears almost circular, or like a square with the two hindmost angles rounded off. It changes in appearance, however, with every new movement of the worm. Eggs were found in as many as six segments or more. ”

“ Mr. Beddard, in his invaluable 'Monograph of Oligochæta,' unfortunately leaves the subject almost untouched. He says (p. 13) : "The cuticle seems undoubtedly to be a formation of the packing cells of the epidermis; the pores upon its surface are the outlets of the gland-cells, and their existence appears to be simply due to the fact that the gland-cells do not secrete a cuticle like the other cells, their secretory activity being taken up in the formation of the granules with which they are laden; hence at the points where they abut upon the cuticle there are gaps—the pores in question." ”