by the bite of a dog indisputably rabid ; but this 

 distemper does not invariably ensue ; neither can 

 it be correctly designated the dread of water, for 

 some dogs lap that fluid readily, from the fever 

 affecting them, though they are unable to swallow it, 

 Instant excision of the wounded part is always 

 considered prudent, where it may be safely per- 

 formed ; and of late, excessive bleeding, such as 

 repeatedly deprives the patient of sense and motion, 

 seems to have been practised with success. More 

 recently, this and some other spasmodic diseases, 

 which are generally found to be incurable by any oi 

 the ordinary modes of treatment, have been treated 

 by inoculation with hydrocyanic (prussic) acid, wourali 

 poison, and some other of those substances or prepa- 

 rations which are most immediately fatal to life. 

 The object is to produce a complete suspension of all 

 the functions of the system a sort of temporary 

 death, as it were ; and then, if the patient can be 

 resuscitated from this temporary death, the disease is 

 found to have left him. This is a desperate means 

 of cure, and may be expected to be in most cases as 

 bad as the disease, in so far as the life of the patient 

 is concerned ; but, even if the application is followed 

 by death, the quantity of suffering is very much 

 abridged by it ; and as there is a ray of hope, though 

 a very faint one, the application is justifiable in 

 extreme cases, but in such cases only. The rationale 

 of the application appears to be this : All spasmodic 

 diseases, or diseases which affect the functions of 

 life rather than any part of the organ'sation, com- 

 pletely cease when life is extinct, without continuing 

 in the form of putridity in the dead subject, as is the 

 case with diseases of the organisation. Hence, if we 

 can cause the life utterly and completely to cease, 

 even for an instant, the disease is destroyed ; and as 

 the life is intimately connected with the organisation, 

 while the disease is not, there is, as it were, a smoulder- 

 ing ember of the one, which lingers for a little after 

 the other is gone ; and if the proper stimuli can be 

 applied to the organisation, so as to make it re-act 

 and the life to return, it returns altogether freed from 

 the disease. How long this power of re-action may 

 continue, is a very nice and delicate, and must vary 

 with the circumstances of each particular case. But 

 the subject is one of the deepest interest, and emi- 

 nently deserving of the most minute, careful, and 

 scientific investigation by those whose profession it is 

 to watch over the health of themselves and their 

 fellow-men. It is of much too abstruse and delicate 

 a nature for popular discussion, and even in the 

 medical world it is new, and safe only in the hands of 

 the most CM nt ions and skilful. 



DOG POISON is the Mtlmm ci/napium or fool's- 

 parsley of Linnaeus, a common British weed. 



DOG'S-BANE is the Apocynum androstcmi/oliiim 

 of Linnaeus ; a flower-border plant of easy culture. 

 The Accmitum cynoctonum of Reichenbach is also 

 called dog-'s-bane. 



DOG'S-TAIL GRASS is the Cynosurus cristaius 

 of botanists, and a valuable agricultural plant, as form- 

 ing a chief part of the herbage on upland meadows 

 and pastures. It is the Hendon Bent, so much prized 

 in the London hay-rnarkets. This grass is always 

 chosen as part of the mixture of seeds for laying 

 down permanent meadows or pasture land. 



DOG'S-TOOTH VIOLET is the Erythronium 

 dens Cants of Linnaeus, a beautiful tuberous-rooted 

 perennial herb, belonging to Hcxandria Monogynia, 



DOG POISON DOLOMEDES. 333 



and to the natural order Liliaceee. See ERYTHRO- 



NIUM. 



DOG-WOOD is the Cornim Suecica of Linnseus. 

 DOLICHOPID.E. A family of dipterous insects 

 belonging to the section Tanystmna of Latreille, com- 

 prising an extensive group of flies, having the body 

 generally compressed, the head triangular and slightly- 

 produced into a muzzle in front, the abdomen curved 

 downwards at the extremity, and the legs very Ion* 

 and furnished with numerous small spines ; the a 

 tennse are short and composed of three joints with an 

 articulated bristle ; the wings have only one or two 

 discoidal cells, the nervures nearly resembling those 

 of the common fly. 



These insects, which are generally found in damp 

 situations, seldom exceed in size the domestic fly, 

 have the body highly ornamented with green and 

 other metallic tints, and in many species various re- 

 markable sexual and other peculiarities are to be ob- 

 served which are not found in other dipterous insects. 

 They reside upon the leaves of plants, where their 

 agility and brilliant colours render them conspicuous ; 

 others are to be seen running along the margins of 

 streams ; they seldom are observed extracting the 

 honey from flowers, but rather sip the dew from the 

 leaves. They walk sideways with as much facility as 

 in a straight line. M. Macquart has observed one of 

 them which had seized the larva of one of the small 

 cicadas, the body of which was half hidden within the 

 large lips between which it was introduced, the sucker 

 of the mouth being at the same time employed in ex- 

 tracting its fluids. According to De Geer, the larva 

 of one of the species resides under ground, where the 

 pupa is transformed. 



There are numerous generic and subgeneric divi- 

 sions established in this group, founded upon structural 

 characters, but which it would be tedious in a work 

 like the present to detail. The typical genus is Doli- 

 chopus of Fabricius, of which there are thirty British 

 species, including the Musca nobilitatis of Linnaeus. 

 The student should consult Mr. Haliday's Memoir, 

 published in the Zoological Journal, No. 19, and 

 that published in a late number of the German 

 periodical, the Isis, in which numerous new species 

 are described. 



DOLICHOS (Linnaeus) is a genus of annual and 

 perennial climbing plants, found in every quarter of 

 ;he world. Class and order Diadelphia Decandna, 

 and natural order Leguminosee. Generic character : 

 ;alyx bracteate, bell-shaped, five-toothed, two upper 

 teeth united ; standard spreading, furrowed at the 

 )ase ; keel angular, incurved, and obtuse ; style flat- 

 tened, bearded above ; pod compressed with contrac- 

 tions between the seed-cells. These plants are easy 

 of culture, growing in any kind of light soil, and may 

 >e propagated by cuttings : the annual sorts by seeds. 

 A great many new genera have been separated from 

 this. 



DOLOMEDES (Latreille). A genus of erratic 

 spiders, having the eyes arranged in a quadrilateral 

 losition, but somewhat broader than long, and in three 

 ines, the anterior of which has four eyes, and the 

 two posterior lines two eyes each, the hinder pair 

 jeing slightly elevated on footstalks ; the second pair 

 of legs is as long as the first ; the lip is short and 

 quare. These spiders do not construct a web, but 

 jhase and run after their prey in the same manner as 

 the Saltici, a very active group, the species of which 

 are constantly to be observed on walls, creeping very 

 X2 



