82 EXPERIMENT STATION RECOKD. 



(Lepus sylvaticus) , at Lethbridge, Alberta; T. pcromyscl, fouud in northern 

 deer mice (Peromyscus maniculatus, P. nehracensis, and other species) at 

 Lethbridge; T. citelH, found in the ground squirrel {Citellus richardsoni) , at 

 Lethbridge; T. rutherfordi, found In the blood of a cow at Mount Lehman, 

 British Columbia; T. evotomys, found in a vole {Evotomys saturatus) at 

 Mount Lehman ; and T. soricis, found in the blood of a wandering shrew 

 (Sorex vagrans) at Mount Lehman. 



Trypanosoma americanura, a common blood parasite of American cattle, 

 H. Crawley {XJ. 8. Dept. Agr., Bur. Anim. Indus. Bui. 145, pp. 30, figs. l5). — 

 This is a report of studies of the nonpathogenic trypanosome described by the 

 author in a bulletin previously noted (E. S. E,., 22, p. 281). 



A resume of the literature, first presented, is followed by reports of (1) the 

 examination of cultures, including seasonal variation in the number of try- 

 panosomes in blood, effect on the trypanosomes of keeping the blood before 

 cultures were made, results obtained with measured quantities of blood, and 

 general results of cultural work; (2) observations on fresh material, including 

 attempts to discover the trypanosomes in freshly drawn blood, evolution of 

 the trypanosomes in culture, movements of trypanosomes in cultures, the 

 pi'ocess of multiplication, and motility of the trypanosomes; and (3) observa- 

 tions on fixed material, including morphology of the forms in the blood and 

 in culture, and cytology of the forms in culture. 



The conclusions drawn are as follows: " T. americanum lives, in all prob- 

 ability as a typical trypanosome, in the blood of perhaps 75 per cent of yearling 

 and adult American cattle, but is not present in young calves. It comes very 

 close to T. ivruhleivski of the European bison, and may be only a variety ot 

 that species. Removal from the circulating blood stimulates multiplicative 

 energy, apparently merely as the result of a cooler environment. Removed 

 from the cow and placed under aiTi^ropriate conditions, multiplicative energy 

 runs far in advance of growth energy; hence the trypanosomes divide and 

 redivide very rapidly, and in consequence become smaller than the blood 

 forms. At the end of a few days, multiplicative energy weakening, the organ- 

 isms have an opportunity to grow and to reach their normal size. The adults 

 are at first very slender, but in time increase in breadth and may become very 

 large. As the cultures reach and pass their maxima the individuals become 

 club-shaped and eventually transform into rounded or oval elements, provided 

 each with a long flagellum. 



" Changes in the morphology of the nuclear system, and in the texture and 

 chemical natui-e or composition of the cytoplasm, accompany changes in the 

 facies of the entire organism. A distinguishing character is the situation of 

 the trophonucleus, which is normally at the union of the anterior and middle 

 thirds." 



A bibliography of 13 titles is appended. 



The infection of mules by Trypanosoma hippicum throug'h mucous mem- 

 branes, S. T. I>ARLix\G (Jour. Expt. Med., 15 {11)12), No. .',, pp. 367-369).— The 

 experiments with mules here reported indicate positively that T. hippicum 

 can penetrate the mucosa of mules. From this it is assumed that murrina 

 may be transmitted during copulation. It is stated that the disease, which 

 has been eradicatetl in the Canal Zone, is still present in parts of the Republic 

 of Panama in villages and along the trails, and that cases have been detected 

 in native ponies near the zone line. 



Investigations in regard to tuberculosis in milch cows, G. Cosco (Ccntbl. 

 Balct. [etc.], 1. Aht., Orig., 61 (1911), No. 1-2, pp. .59-63).— Tuberculosis may 

 be conveyed from one bovine to another by the agency of the feces, which 

 contahis the specific living and virulent organism. Some cows, which to all 



