BOTRYOGENE. 



BOTS. 



610 



Sidnyum, Sav. The mass presents the appearance of a number o] 

 heads of Madrepore or Cladocora, each formed of a simple cone trun- 

 cated and starred at the summit, rising from a common encrusting 

 base, the whole being grouped closely together. There is but one 

 species, S. turbinatum, which occurs abundantly on the north coast ol 

 the Isle of Man and other parts of the British Islands. 



Polyclinum, Sav. Mass sessile, gelatinous, or cartilaginous ; poly- 

 morphous, composed of more or less multiplied systems, convex, 

 radiated, each having a central cavity, and being more or less 

 distinctly circumscribed. Individuals 10 to 150, placed at unequal 

 distances form a common centre. P. aurantium, Milne-Edwards, 

 has been found at Cullercoats. 



Amouraucinm, Milne-Edwards. Mass lobed or encrusting, sessile or 

 pedunculated, fleshy or cartilaginous, composed of many systems, each 

 having a central cavity. A. proliferum, M. Edwards, has been found 

 in Belfast Bay. A. Nordmanni, M. Edwards, and A. Argus, M.Edwards, 

 have been token at Falmouth by Mr. Alder. 



Leptoclinum, Milne-Edwards. Mass thin, sessile, encrusting, poly- 



_ morphous, coriaceous or gelatinous, composed of many systems ; 



vents opening into a common cloaca. The following species have 



been taken on various parts of the British coasts : L. tnaculosum, 



L. asperum, L. aureum, L. gelatinornm, L. Listarianum, L. punctatum. 



Ditoma, Gaertner. Mass sessile, semicartilaginous, polymorphous, 

 composed of many systems, usually circular. Anal and branchial 

 orifices regularly and equally 6-rayed. Two species, D. rubrum and 

 D. rariolosum, are British. 



Solryllui, Gaertner. The animals are grouped in single stars, and 

 t lie horizontally with the vent far from the branchial orifice. The 

 branchial orifices simple and arranged around a common cloaca. 

 B. AMouerl, Pallas. This is the species figured by Schlosser in the 

 ' Philosophical Transactions.' It is one of the most beautiful, as it is 

 one of the most common species of the family. Living specimens of 

 this and the other species of Botryllidce are now in the Aquavivarium 



o, A group otSotryllut Schlosseri upon Aicidia Meitinalit ; b, a diek magnified. 



of the Zoological Society in the Regent's Park Gardens. The other 

 British species are B. polycyclue, Savigny ; B. gemmeus, Sav. ; B. vio- 

 laceiu, Milne-Edwards; B. Smaratjdu*, M. Edwards; B. bivMatui, 

 M. Edwards. 



Botrylloides, Milne-Edwards. The stars formed by the systems of 

 these animals are irregular and ramifying. The bodies are placed 

 vertically and the two orifices approximate. The following species are 

 British : B. Leachii, Sav. ; B. albican, M. Edwards ; B. rotifera, 

 M. EVlwards ; B. rubrum, M. Edwards. 



(Forbes and Hanley, History of British Afollusca.) 



BOTRYOGENE, native red Sulphate of Iron. It occurs crystallised, 

 the crystals being usually aggregated in globular reniform and botry- 

 oidal masses. The primary form is that of an oblique rhombic prism. 

 The colour is deep hyacinth-red and ochre-yellow with a yellow 

 streak. The hardness is from 2'25 to 2'5. The lustre vitreous ; 

 translucent. The taste slightly astringent. The specific gravity 

 2-039. It is composed of 



Sulphuric Acid 32'55 



Peroxide of Iron 23'86 



Protoxide of Iron 1071 



Water 32-85 



It is found in the great copper-mine of Fahlun in Sweden. 



BOTRY'TIS, one of the obscure parasitical genera of Fungi, to 

 which what is called Mildew is often attributable. The plants consist 

 of little cells adhering end to end ; of these a part lies prostrate on 

 the surface of the plant that bears them, the other rises erect from 

 thp Hiirface and bears a collection of roundish seed-cases at the extre- 

 mity. From the spores contained in these cases the plants are propa- 

 gated, and seeing that their size is so microscopic in all cases as to 

 escape our vision unaided by glasses, and that what seems to the 

 naked eye a thin brownish white patch upon a leaf is in reality a 

 dense forest of such plants, their power of dissemination must be very 

 great. They attack the fibres of vegetable fabrics, such as linen and 

 cotton when placed in damp places, and the decayed stems of various 



HAT. HIST. DIV. VOL. I. 



plants, decaying apples, pears, grapes, &c. They are always superficial, 

 and never intestinal. 



BOTS are the Larvse or Caterpillars of the Gad-Fly, belonging to 

 the order D-iptei'a and the genus (Estrus, and distinguished by this 

 peculiarity, that they pass the larval state of their existence within 

 some living animal, and feed on the juices or substance of that animal. 

 There are numerous species of them. Every quadruped on which 

 they prey has its peculiar fly. The notice of a few of those most 

 commonly known will suffice. 



The Oestrus Equi, or Gad-Fly of the Horse, belongs to the genus 

 Gasterophilus of some entomologists, so called from its larvae inhabiting 

 the stomach of that animal. It is distinguished from the other (Estri 

 by the smoothness of the thorax, and by the eyes in both sexes being 

 equidistant from each other, not quite half an inch in length, with 

 gauze-like yellow and brown wings, its chest of a rusty colour 

 approaching to a brown hue on the sides and with a yellow tinge 

 posteriorly, its belly of a reddish-brown superiorly and a dirty gray 

 beneath, with its extremity almost black. The whole insect is thickly 

 covered with down. The Gad-Fly is seen in the latter part of the 

 summer very busy about horses : this is the impregnated female 

 depositing her eggs. She approaches the horse, selects some part 

 which he can reach with his tongue, and which he is in the frequent 

 habit of licking ; she balances herself for a moment, and then suddenly 

 darting down, deposits an egg on one of the hairs, which adheres by a 

 glutinous substance that surrounds it. She continues her labour with 

 wonderful perseverance until she has parted with fifty or a hundred 

 eggs, and then having exhausted herself, she slowly flies away, or 

 drops at once and dies. 



If a horse at grass is carefully examined in August, some hundreds 

 of these minute eggs will be found about its legs and the back part of 

 the shoulder, and few or none out of the reach of his tongue. In two 

 or three days these eggs are sufficiently matured to be hatched. 

 Possibly the horse feels a little inconvenience from all this glutinous 

 matter sticking about and stiffening the hair, and he licks the part, 

 and by the pressure of the tongue, and the mingled influence of the 

 warmth and moisture of it, the ova are burst, and a small worm 

 escapes from each. It clings to the tongue, and is thus conveyed into 

 the mouth ; thence it is either earned with the food into the stomach, 

 or, impelled by instinct, it travels down the gullet, being too small to 

 inconvenience or annoy the horse. Thus it reaches the stomach, and 

 by means of a hook on each side of its mouth affixes itself to the 

 cuticular or insensible coat of that viscus. It scoops out a little hole, 

 into which its muzzle is plunged, and there it remains until the early 

 part of the summer of the following year, feeding on the mucous or 

 other matter which the coats of the stomach afford. It has now 

 become an inch in length and of corresponding bulk, and ready to 

 undergo its change of form. It detaches itself from the cuticular 

 coat to which it had adhered, and plunges into the food which the 

 other and digestive portion of the stomach contains ; it passess with 

 the food through the whole length of the intestines, and is discharged 

 with the dung. Sometimes it is not perfectly enveloped in the fecal 

 mass ; it then clings to the sides of the anus, and hangs there firmly 

 until there is a soft place beneath on which it may drop ; it then 

 hastens to burrow into the earth, and, if it has escaped the birds that 

 are eagerly wp.tching for it, it has no sooner hollowed for itself a 

 convenient habitation than a shelly covering is formed around it, and 

 it appears in the state of a pupa or chrysalis. 



It here lies torpid for a few weeks, preparing to undergo its last 

 change. It assumes the form of a perfect fly ; it then bursts from its 

 prison, rises in the air, and seeks its mate. The work of fecundation 

 being accomplished, the male immediately dies : the female lingers a 

 day or two in order to find the proper deposit for her eggs, and her 

 short life also terminates. 



It is in the larva or caterpillar state that the Bot is most known. 

 The stomach of the horse sometimes contains an almost incredible 

 number of them, the cuticular portion of that organ being in a 

 manner covered with them. In a few instances they have been 

 decidedly injurious. Having mistaken the upper part of the windpipe 

 for their residence, and fastening themselves on the edges of the 

 opening into it, have produced a cough which no medicine could 

 alleviate, and which increased with the growth of the Bot, until a 

 degree of irritation was excited under which the animal sunk. They 

 have also travelled farther than the stomach, and have irritated and 

 choked the first intestine, and thus destroyed the horse ; and, even 

 in their natural habitation, under probably some diseased state of the 

 stomach arising from other causes, they have perforated it and 

 caused death. 



These ' however are rare occurrences ; they are exceptions to a 

 general rule. The plain matter of fact is, that a horse that has been 

 turned out in July and August, and therefore almost necessarily has 

 Dots, enjoys just as good health as another that has been stabled 

 during this period. He is in as good condition, and as fully capable 

 of work when the cuticular coat is crowded with full-formed bots as 

 le is at any other time ; and his health is unaffected when they are 

 aassing through the intestines to seek a new habitation. 



A smaller species of Bot, called from its colour the Red-Bot, is 

 occasionally found in the stomach ; but the fly from which it proceeds 

 las never been accurately described. There is no ground for 



2 B 



