42 Observations on Parasites and Parasitic Diseases 



plate, much darker in colour than the rest of the skin, is placed 

 evidently to give streng'th to this part of the frame. On the 

 under surface of the abdomen, just behind the last pair of legs, 

 a circular-shaped respiratory organ exists on either side ; and 

 a little further backwards a similarly-shaped body centrally 

 placed, having a slit in its middle, is also present. The latter 

 named opening is the excretory outlet to both the digestive and 

 reproductive systems (See Fig. 2). 



Although, as has been stated, these parasites are comparatively 

 harmless in this country, still, in many parts of South America 

 they attack animals in such great numbers as to give rise to 

 serious consequences, and often indeed to cause death. At a 

 meeting of the Microscopical Society in 1842, Professor Busk 

 exhibited some living ticks which had been sent him from Rio 

 Janeiro as specimens of the parasite, called by the Brazilians the 

 CarafQto, which had been from sixty to seventy days on their 

 passage. At a subsequent meeting of the same Society, Mr. 

 Busk read an interesting Paper, containing much practical in- 

 formation, on the subject, from which we make the following 

 extracts : — 



" 1. The name of Carpato or Carapat is given to the insect, in consequence 

 of its resemblance to the seed of the Eicinus, which has that name in 

 Portuguese. 



" 2. It is common in all parts of South America, where cattle abound, 



" 3. It infests cattle, horses, dogs, and sheep. 



" 4. It is not found on plants ; and cattle generally become infested with it 

 when feeding in open and exposed pastures, where the sun's heat is great ; and 

 it increases most in dry seasons. It is generally supposed that the insect was 

 not seen in the Brazils previously to an excessively hot and dry summer about 

 1824 or 1825, since which it has multiplied amazingly. It is remarkable that 

 cattle feeding in shady pastures and coppices are frequently quite free from the 

 carpato, but will acquire it by infection from others. 



" 5. The mode in which it appears to cause destruction to the animal infested 

 by it, is by the incessant irritation which prevents the animal feeding or rest- 

 ing, and in consequence it becomes worn out. 



" 6. They first appear on those parts of the skin imcovered by hair, and are 

 then not larger than a pin's head, but make the part quite black by their 

 numbers. They adhere so closely, that scraping them off would tear up the 

 skin. In a short time they increase to the size of a bean, or common tick, as 

 seen in dogs, and fix themselves promiscuously on all parts of the hide where 

 covered with hair. 



" 7. The same species appears to insinuate itself, in its incipient state, upon 

 the human body ; but is not known to assume the tick form there. They 

 adhere tenaciously to the skin, and are believed to introduce themselves below 

 it. They are very harrassing, and even create soreness and inflammation. 

 They generally affect persons who have been passing through woods, but are 

 not known to be ever seen or found on trees or plants. 



" 8. Many thousand head of cattle are annually carried off by the carpatoes, 

 and frequently a scarcity is thus caused." * 



* ' Microscopical Transactions,' vol. i., p. S8. 



