British medical journal . reach the adult stage,when they make their escapethrough an orifice generallyat the hind end, leaving be-hind them the dead body oftheir host. Three species ofsuch hemipterous insects areknown, parasitic on ticks, ofthese Ixodiphtifjus caucuriei isubiquitous. It attacks allkinds of ticks, but especiallyDermacentor venustus. Ixodes ricinua,ot a in the male, is verycommon in England and, in-deed, almost everywhere. Thefemale is yellow and flattened,grain of rice. It is tho well-known dog tick, but it attacksoxen, especially goats, deer, horses, and man.
British medical journal . reach the adult stage,when they make their escapethrough an orifice generallyat the hind end, leaving be-hind them the dead body oftheir host. Three species ofsuch hemipterous insects areknown, parasitic on ticks, ofthese Ixodiphtifjus caucuriei isubiquitous. It attacks allkinds of ticks, but especiallyDermacentor venustus. Ixodes ricinua,ot a in the male, is verycommon in England and, in-deed, almost everywhere. Thefemale is yellow and flattened,grain of rice. It is tho well-known dog tick, but it attacksoxen, especially goats, deer, horses, and man. It alsoattacks the grouse, and is particularly common in someparts of Great Britain. It is impossible to rid certainareas of these troublesome guests. In some cases theyproduce tumours and introduce bacteria, and in cattleit introduces an organism known as Babesia hovis,which is the cause of haematuria in oxen. Dermacenlorvenusius transmits Rocky Mountain fever, which iscommon in certain parts of the States. The fever isC. accompanied -with pains in the joints and muscles and aneruption on the surface of the skin, appearing on thewrists and forehead, and invading in time all parts ofthe body, followed by a scaling of the .skin duriug a periodof convalescence. In Montana the mortality caused bythis disease is very high, varying in different years from33 to 75 per cent. In Idaho it only attains a mortality of4 per cent. Ornithodorusmouhataxaocv\a, with a spirochaete(SjyirocJiaeta duttoni) which is the agent of the Africantick fever or relapsing fever. One of the curiosities aboutthe organisms transmitted by ticks is that they livethrough the whole cycle of the ticks life. If they aretaken in by the larva they are only transmissible by thefollowing larval stage. If they are taken in by the nymphthey are only transmissible when the nymph stage ismet with, and the same is true of the adult. Think whatsuch a .protozoon must have seen I The theegg
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectmedicine, bookyear185
