266 THE PROTOZOA 



Some prefer to inoculate susceptible animals, particularly the guinea-pig or 

 monkey, with blood or gland juice from the suspected case. A very satisfactory 

 material is an emulsion from an excised gland which may be inoculated intraperi- 

 toneally into white rats. The further course, after animal inoculation, is the ex- 

 amination of the blood of these animals for trypanosomes. Usually at the time the 

 guinea-pigs die we find numerous trypanosomes. 



Other tests are (i) Trypanolysis, when unheated suspected serum and trypano- 

 somes are incubated together for one hour. Normal serum may occasionally cause 

 disintegration and treated cases give it in only about 45% of cases. Unfavorable 

 untreated cases give it in about 80% of cases. 



(2) The so-called auto-agglutination test is not of much value. In this the red 

 cells of the blood of a trypanosomiasis case come together in clumps when one 

 makes a wet preparation. It is not a rouleaux formation. (3) The attachment test 

 is made by making a mixture of inactivated serum, leukocytes and trypanosomes 

 and allowing them to be in contact for twenty minutes. A positive test shows 

 attachment of the trypanosomes to the leukocytes. 



Of the more important trypanosome diseases of animals may be 

 mentioned: 



1. Nagana. Pathogenic for domesticated animals in South Africa. T. brucei. 



2. Surra. Pathogenic for horses in India and Philippines. T. evansi. 



3. Dourine. Transmitted by coitus in horses. T. equiperdum. 



4. Mai de caderas. Affects horses in South America. T. equinum. 



A harmless infection, especially in sewer rats, is due to T. levrisi. Transmission of 

 this rat trypanosomiasis can apparently be brought about through the agency of 

 both fleas and lice. In the flea there is apparently a developmental cycle of a dura- 

 tion of one week. 



There are many trypanosomes in birds, fish, frogs, etc. 



Schizotrypanum cruzi (Trypanosoma cruzi). In 1909, Chagas re- 

 ported the finding of a flagellate in the intestines of Conorhinus megistus 

 or, more properly, Lamus megistus. He was also able to transmit the 

 flagellate to laboratory animals and could culture it on blood agar. 



In investigating the matter of the importance of this flagellate, 

 Schizotrypanum cruzi, in Minas Geraes, Brazil, where the bug was pres- 

 ent in great numbers in the cracks of the houses of the poor, he asso- 

 ciated this flagellate infection, which he at first considered trypano- 

 somal, with a disease of the children of that section. 



The bug is a vicious feeder and, from its biting chiefly about the face, has been 

 called barbiero or barber by the natives. Both the male and female of Lamus bite 

 and can transmit the disease and although the parasite is not transmitted hereditarily 

 the nymph is capable of sucking blood and becoming infected. 



It requires several months for the insect to go through the egg, larval and pupal 

 stage to maturity. Some consider this bug to belong to the genus Triatoma. The 

 insects may live for more than a year and tend to remain in the same house where 



r or 



