872 



TITAN OTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



of trematodes are commonly parasitic among the 

 Herbivora in tropical countries. They infest the 

 stomach and intestines in great numbers and not only 

 deplete the animal's energy by exacting a great 

 quantity of blood but disturb the lining membrane of 

 the stomach and intestine so as to interfere seriously 

 with the secretions and digestion. Several species of 

 worms may be found in the same region. 



When it is suffering from the attacks of these 

 parasites the elephant is said to make instinctively an 

 attempt to get rid of them by eating 10 to 20 pounds of 

 a certain red earth, which acts as a purgative, dis- 

 lodging and expelling a lot of worms. In India, where 

 there are domesticated herds of 400 or 500 of these 

 valuable animals, the loss from Entozoa is sometimes 

 serious. 



Parasites in air sinuses. — Larvae that invade the 

 frontal sinus of the skull are among the possible 

 causes of the extermination of animals. An old 

 trapper and close observer in British Columbia, Mr. 

 Charles Smith, informs the author that both the wild 

 sheep of the region {Ovis montana) and the wapiti 

 {Cervus canadensis) are seriously affected or killed 

 by inflammation caused by these larvae. The over- 

 crowded caribou of Labrador and Newfoimdland 

 suffer from a fly which lays its eggs in the nasal 

 passages. 



Allen (1906.1, p. 201) states that there is a patho- 

 logic modification in the skulls of peccaries {Tayassu), 

 due to parasites lodging in the orbitosphenoid and 

 adjacent parts. He observes: 



In this connection an examination has been made of nearly 

 50 skulls of peccaries, in the [American] Museum collection 

 from various parts of South Amierica, with the following 

 results: In a series of 17 skulls of T. pecari from Santa Marta 

 district of Colombia, all were found diseased in the manner 

 above described, so that this condition might readily be mis- 

 taken for the normal. In 20 skulls of T. torvum about 80 per 

 cent show the diseased condition strongly, and others show 

 traces. Of 9 skulls of T. iajacu from Chapada, Matto Grosso, 

 Brazil, 2 only are normal. The inflation of the bones forming 

 the antero-inferior wall of the orbit, through the invasion of 

 these parts by some parasite, is so general in the whole group 

 of peccaries that the absence of such conditions seems to be 

 almost exceptional. 



Moisture favoring the spread of diseases carried by 

 insects. — The presence of the blood protozoan para- 

 sites known as trypanosomes, combined with certain 

 fhes which act as disease carriers, is in many countries 

 correlated with wet weather. This is especially true 

 of the disease known in India as "surra," the history of 

 which was first suspected by Surgeon Major Lewis in 

 1888 (1888.1). In South America the mal de caderas 

 affects horses, asses, cattle, hogs, and certain other 

 animals and is attributed to the protozoan known as 

 Trypanosoma equinum. It is distinctively a wet- 

 weather disease, almost completely disappearing in 

 dry seasons. Asses, swine, and water hogs are said 

 to be affected, and horses are never known to recover. 



It is chronic in course, lasting fi-om two to five months 

 in horses and from six to twelve in asses and mules. 

 See Voges (1902.1) for fuller details. 



Extermination of the Equidae. — The wide geographic 

 range of surra and related diseases is significant with 

 reference to former periods in the history of the 

 Equidae. All authors now agree with Lewis that the 

 disease is carried by flies and coincides with wet 

 weather, occurring chiefly during or immediately after 

 heavy rainfall, though sporadic cases may occur at 

 other seasons of the year. In the "Emergency 

 report on surra" by D. E. Salmon, C. W. Stiles, and 

 A. Hassall (1902.1, p. 18), this is described as chiefly 

 a wet-weather disease, invariably fatal to horses and 

 mules, occurring in other animals, such as camels and 

 elephants, more rarely in ruminants, and transmis- 

 sible to goats, sheep, and other mammals. In India 

 it is said to affect horses, camels, and elephants. It 

 occurs in Burma, Persia, Tonkin, and Chosen. In 

 Africa there is the similar nagana, or tsetse-fly disease, 

 more accurately described by Bruce (1905.1, p. 333). 

 In Algiers, France, and Spain the dourine or maladie 

 de coit attacks the horse and ass in particular and 

 may be transmitted to certain other animals. It is 

 attributed to a trypanosome, T. equiperdum. In the 

 Philippines surra caused the death of 2,000 army horses 

 in six months. The intermediary is a fly, Stomoxys 

 calcitrans. It was also reported (Curry, 1902.1) as 

 affecting the carabao. Bos (Buhalus) Tcerabau, but 

 according to Lingard ruminants are not particularly 

 susceptible. 



An interesting bit of advice given to those in 

 charge of horses in the Philippines may have some 

 bearing upon the origin of colors in certain quadru- 

 peds: "Avoid light-colored animals as much as 

 possible; the darker the animal the safer he appears 

 to be from the attack of flies." In this connection 

 we recall the dark color of the true Bovinae, the wild 

 cattle. 



Tsetse-fly disease of domesticated Equidae and 

 Bovidae. — The nagana or tsetse-fly disease of Africa 

 is caused by Trypanosoma brucei (Plimmer and 

 Bradford, 1889-1; 1902.1); the carrier is the tsetse 

 fly (Glossina morsitans). Together this trypanosome 

 and its host, the fly, render thousands of square miles 

 of Africa uninhabitable; no horses, dogs, or cattle can 

 venture even for a day into the "fly country." After 

 all the nonimmune animals of the country have been 

 killed off and thus there no longer exist sources of 

 infection, the tsetse fly spreads abroad out of the "fly 

 country," still giving rise to the disease. This strange 

 fact led to the discovery of the fact noted above — 

 that many of the immune wild ruminants carry the 

 same trypanosome {T. hrucei) in small numbers in 

 their blood and thus act as continuous reservoirs of 

 the infection; it is from them that the fly receives 

 fresh supplies of the infectious parasite. A similar 



