Convolvulus

“ Emily found a smear of blood on a beautiful trail of yellow convolvulus. We followed the tracks on to the open, where the brook flowed on the hard rock bed, and the stony floor of the quarry was only a tangle of gorse and bramble and honeysuckle.
“Take a good stone,” said I, and we pressed on, where the grove in the great excavation darkened again, and the brook slid secretly under the arms of the bushes and the hair of the long grass. We beat the cover almost to the road. I thought the brute had escaped, and I pulled a bunch of mountain-ash berries, and stood tapping them against my knee. ”

“ We shall show presently that the Convolvulus was one of the Lepidoptera or Butterflies; the Volucra or Volvox must belong to a totally different class. Now among insects there are only the larvæ and the insects of the Coleoptera, and the caterpillars or larvæ of the Lepidoptera, which are very injurious to the vine; the Volucra or Volvox must therefore belong to the class Coleoptera. Besides, we learn from Pliny and Columella that the Volucra or Volvox infested both the young shoots and the grapes. Pliny says, "Volvocem animal prærodens pubescentes uvas;" ”

“ Max Weber found it in small streams in Malaysia. It is common in India on the leaves of Vallisneria and Limnanthemum, on the roots of Pistia stratiotes and on the stems of rushes and grass. So far as I have been able to discover, the life of the individual sponge is short, only lasting a few weeks.
Sexual reproduction occurs seldom or never, but reproduction by means of buds and gemmules continues throughout the year. The former is a rare method of reproduction in most Spongillidæ but in this species occurs normally and constantly, the buds being often very numerous on the external surface. ”

“ Although long known to Conchologists, it still continues a rare shell to our cabinets, and is much sought for on the continent, particular among the collectors in Holland; they view it with something of a national fondness, and value it at a high price. It is brought from Amboyna, and some other islands of the Indian Ocean. The many-plaited Volutes, form one of the most natural groups in the whole department of Conchology; and one which the most unpractised student will have no difficulty in understanding. ”

“ In form it approaches nearest to Conus vitulinus of Bruguiere, having the spire not quite depressed, each volution being slightly raised above the last, gradually to the apex; the upper margin of the body whorl is convex: each volution of the spire has a broad and deep groove nearest the upper edge, which thus becomes elevated, while the convexity of the lower part of the whorl forms a channel round the suture, which separates it from the next; this formation of the spire is very remarkable, and unlike what I have seen in any other Cone. ”

“ Laurent observed reproduction by splitting in young individuals of Spongilla, but I have not been able to obtain evidence myself that this method of reproduction occurs normally in Indian species. In injured specimens of Spongilla carteri, however, I have observed a phenomenon that seems to be rather an abnormal form of budding, little rounded masses of cells making their way to the ends of the radiating skeleton fibres and becoming transformed into young sponges, which break loose and so start an independent existence. ”

“ The mouth remains in many species constantly open, even when the frontal fissure is closed (figs. 7, 16) . Since the centre of the shell mouth lies in the prolongation of the proboscis arising from the operculum of the central capsule, probably the main stream of sarcode, issuing from the latter, becomes protruded by the former.
Apophyses of the shell (besides the teeth of the margins) are completely wanting in three genera, Concharium, Conchellium, and Conchopsis (Pl. 123, figs. 1-4, 7; Pl. 125) . The four other genera possess free apophyses or spines, which we call horns. ”

“ In Spongilla proliferens, a common Indian species, the buds arise [Pg 45] as thickenings of the strands of cells accompanying the radiating spicule-fibres of the skeleton, which project outwards from the surface of the sponge. The thickenings originate beneath the surface and contain, at the earliest stage at which I have as yet examined them, all the elements of the adult organism (i. e. flesh-spicules, ciliated chambers, efferent and afferent canals, parenchyma-cells of various sorts) except skeleton fibres, gemmules, and a dermal membrane. ”

“ In the adult state the female Echinorhynchus gigas is a huge species, occasionally reaching two feet in length, with a breadth of one third of an inch. The male rarely exceeds three inches. This worm is common in swine, both wild and domesticated. According to Schneider the embryos take up their residence in the grubs or larvæ of the cockchafer (Melolontha vulgaris) , a discovery which very readily explains the manner in which hogs become infested. Whether E. gigas be a human parasite or not, it is certainly very injurious, not to say destructive, to swine. ”

“ The most abundant and possibly the most important organisms that may be considered as benefactors to the Spongillidæ are the green corpuscles that live in the cells of certain species (fig. 2, p. 31) , notably Spongilla lacustris, S. proliferens, and Dosilia plumosa. I have already said that these bodies are in all probability algæ which live free in the water and move actively at one stage of their existence, but some of them are handed on directly from a sponge to its descendants in the cells of the gemmule. ”

“ These cells give the whole sponge a faint pinkish tinge during life; but if it is plunged in spirit, both the liquid in the cells and the spirit turn rapidly of a dark brown colour. Specimens of Spongilla crateriformis taken in a certain tank in Calcutta during the cold weather had the majority of the skeleton-spicules blunt, while the extremities of the gemmule-spicules were distinctly differentiated. Specimens of the same species taken from the same tank in July had the skeleton-spicules pointed, while the extremities of the gemmule-spicules were much less clearly differentiated. ”

“ As they exist in the cells of Spongilla the corpuscles are minute oval bodies of a bright green colour and each containing a highly refractile colourless granule. A considerable number may be present in a single cell. It is found in European sponges that they lose their green colour if the sponge is not exposed to bright sunlight. In India, however, where the light is stronger, this is not always the case. ”

“ The genus Conchidium is the most common form of all Concharida, and some of its species occur in great numbers in the tropical zone of the Pacific and the Atlantic, on the surface as well as at various depths. It differs from the preceding Conchellium, its ancestral form, in the development of two caudal horns, or two strong pyramidal spines which arise from the posterior end of the valves; the dorsal horn usually is smaller than the ventral. ”

“ The genus Conophis Peters, 1860, contains four species. Three are monotypic and the fourth has three subspecies, making a total of six taxa.
The genus is characterized by maxillary teeth of equal size followed by a diastema and two enlarged grooved fangs. The scales are smooth, in 19 rows at mid-body, and 17 nearer the tail. The anal is divided, apical pits are lacking, the head shields are normal for a colubrid, and the hemipenis is bilobed having many large basal spines. ”

“ An animal that may be an enemy of S. carteri is a flat-worm (an undescribed species of Planaria) common in its larger canals and remarkable for the small size of its pharynx. The same worm, however, is also found at the base of the leaves of bulrushes and in other like situations, and there is no evidence that it actually feeds on the sponge. Injured sponges are eaten by the prawn Palæmon lamarrei, which, however, only attacks them when the dermal membrane is broken. A Tanypus larva (Chironomid [Pg 93] Diptera) that makes its way though the substance of the sponge may also be an enemy ”

“ The Central Capsule of the Spongurida is either ellipsoidal or cylindrical. Only in Spongellipsis it lies freely in the internal cavity of the spongy shell. In all other genera it is perforated by a part of the skeleton; in the Spongodruppida it contains the simple or double medullary shell, and the radial beams which perforate its membrane and connect the latter with the external spongy cortical shell. In Spongurus and the allied genera (Spongocore, Spongoprunum) the whole central capsule is filled with a spongy framework which also envelops its surface. ”

“ The tail of the female is curved upon itself, rounded off, and drawn out at the extreme end into a straight beak-shaped point; whilst to both sides of the stumpy caudal extremity of the body short vesicular prominences are attached. The female reproductive outlet occurs at the commencement of the second half of the body. Thus, judging by its external characters this genus is most closely allied to Strongylus.” In reproducing Diesing’s description I have here rendered the translation somewhat more freely than in my previous record of the discovery given in ‘Nature’ (1871) . ”

“ The Bothriocephalus latus and the Tænia solium, are two kinds of tape-worm, which flourish in the human intestines; producing great constitutional disturbances, sometimes ending in insanity; and from the germs of the Tænia, when carried into other parts of the body, arise certain partially-developed forms known as Cysticerci, Echinococci, and Cœnuri, which cause disorganization more or less extensive in the brain, the lungs, the liver, the heart, the eye, &c., often ending fatally after long-continued suffering. ”

“ This cavity has as a main function that of a digestive cavity.
An ideally simple cœlenterate would not differ much in general appearance from an olynthus (p. 27) , but it would have no pores in the body-wall and its upper orifice would probably be surrounded by prolongations of the body-wall in the form of tentacles. There would be no collar-cells, and the cells of the body generally would have a much more fixed and definite position and more regular functions than those of any sponge. The most characteristic of them would be the so-called cnidoblasts. ”

“ As a rule adult Demospongiæ have several or many oscula, but even in the Spongillidæ sponges occur in which there is only one. New oscula are formed by a kind of proliferation that renders the structure still more complex than it is when only one exhalent aperture is present.
The little arrows in the figure indicate the direction of the currents of water that pass through the sponge. It enters through small holes in the derma into a subdermal cavity, which separates the membrane from the bulk of the sponge. This space differs greatly in extent in different species. ”

“ From these animals the proglottides pass into the water in the ordinary way. The ova are subsequently swallowed by sunfishes and other intermediate hosts, within whose stomachs the six-hooked embryos are liberated, and the scolices become developed in the ordinary manner. As obtains in Cysticercus fasciolaris of the mouse the scolex of Tetr. reptans becomes tænioid. I have seen the liver of an adult sunfish so infested by these parasites that the whole organ might be fitly described as a mere bag of worms, the immature strobiles being inextricably coiled together and defying separation. ”

“ Sexual dimorphism is evident in all species and subspecies of Conophis. Differences always exist in the number of subcaudals and in the tail/body ratio; males have more subcaudals and relatively longer tails than do females (table 3) . ”

“ This is unfortunate, because many other parasites prove destructive to lambs. One of the most injurious species is Strongylus contortus, infesting the true stomach, whilst S. hypostomus, occupying the small intestines, is almost equally obnoxious to the ovine bearer. By Leuckart and others this last-named worm is retained in Dujardin’s genus Dochmius, in which genus another species occurs (D. cernuus) . This worm is quite distinct, but not readily distinguishable by the naked eye alone. It occasionally occupies the upper part of the colon, as well as the lower end of the small intestine. ”

“ Spongillidæ differ greatly in consistency. Spongilla crassissima and Corvospongilla lapidosa are almost stony, although the former is extremely light, more like pumice than true stone. Other species (e. g., Trochospongilla latouchiana) are hard but brittle, while others again are soft and easily compressed, as Spongilla lacustris, the variety mollis of S. carteri, and S. crateriformis. The consistency of a sponge depends on two factors—the number of spicules present, and the amount of spongin. In Corvospongilla lapidosa the number of spicules is very large indeed. ”

“ Definition.—Concharida with dentate lateral margins and a sharp sagittal keel of the compressed valves, without horns on the hinge.
The genus Conchopsis and the following Conchoceras differ from the other Concharida in the strong lateral compression of the shell, so that each valve is provided in the sagittal plane with a sharp prominent keel, comparable to the dorsal and the anal fin of fishes. These compressed shells are in general twice to three times as large as the more roundish and keelless shells of the five preceding genera. ”

“ There is much variety in the larvae; some of them bear large, complexly-spined, projections; those of the group Scymnites have small depressions on the surface, from which it has been ascertained that waxy secretions exude; but in Scymnus minimus no such excretions are formed. Certain species, when pupating, do not shuffle the skin to the extremity of the body, but retain it as a covering for the pupa. The larvae that feed on plants are much less active than the predaceous forms. We are well supplied with Coccinellidae in Britain, forty species being known here. ”