•tfi 



WIMM. TUYrWOSnMI ASF.S IN THK Wr.r.O-r.r. YI'TI AN SI'PAN 



with no frou lliincllnin. TIrtu arc, of coiiisu, i,'rtulat,i(iMs lictwccti tlio two, ami lliis 

 (listiiictioii, tlioiit^li voiy coiivoiiicnt, is not intentltifl to hv aii)itiary. An interesting point, 

 liowt'ver, has been noticed here during observations made on llic disease in j^erbils. It has 

 i)cen foiin<l tliat, in a eonnnencinji infection, the lonf^ slen(hT forms are the first to appear 

 and tlie stout forms are not found till tiie infection is well advanced ; further, these forms 

 are very much in evidence in the closing phases of the disease. 



[b) Fixed and utained. In general, the films were stained here simply by the ordinary 

 Leishman method. Osmic acid fixation with (iiemsa stain was also used. Studied in this 

 way, the two forms mentioned above are very apparent but, as stated, there is no distinct 

 line of demarcation between the two, intermediate forms being easily recognised. 



heiKjth. — The measurements are made, as explained in the introduction, after Bruce's 

 principle, many of the tables below being compiled directly from measurements so kindly 

 undertaken and ri'sults olitained Ijy Colonel Sir David ]5ruce in his Londim Laboratories, 

 and to whose courtesy and help we are so mucli indi'btcd in ))n'])aring tliis ))a))er. 



Table 1. Measurements of Trypanosomes of Tyjie 1 ('/'. Unirei). 



Dim- 



.ranunry 27, 1906 

 February 2, 1908 

 February 11, 1908 

 November 20, 190s 

 December 12, 1910 

 December 21, 1910 

 .T.immrv 1, 1911 



. . , Method of fixing 



•^"""•'' and s.aininK 



Kilt 



Gcrbil ... 



Qerbil ... 

 IMonkoy 2 



(ierl)il ... 



Ocrbil ... 



Ocrbil ... 



In microns 



Average 

 Length 



Ijeishuiaa 

 Tjoishman 

 rjoisliman 



22-9 

 211-7 

 21-2 

 lG-8 

 22-9 

 21-4 

 2G-4 



Maximum 

 Length 



Minimum 

 Length 



.'U-O 

 28-0 

 33-0 



2.')-li 

 .■i7-ii 

 27-0 

 :U-0 



14-0 

 l(l-0 

 16-1) 

 14-11 

 IG-ii 

 I.-.-ii 

 l,S-() 



Measurements 

 ' by Colonel 

 I Sir David 

 Bruro, 1910 



MiNisiiromi'iits 



KliartoHiii, 



l)eccmborl910- 



.lanuarv 1911 



Gross average 



oo.o 



30-7 



15-6 



In comparing this table with Bruce's own measurements of 7'. briicei of the original 

 Zululand strain discovered by him in 1894, we are at once struck by the resendjlance. 



In the above table, twenty trypanosomes Avere measured in each case, and from 

 these the average length was obtained, the length of the longest and shortest form 

 being also given. 



It must again be emphasised that these tables have their value rather as a synthetic 

 whole than for detailed analysis, and that discrepancies in detail nmst not be allowed 

 an undue importance. For instance, the table shows a variation in maximum lengths 

 between 27 and 34 microns in the last two cases. We liave mentioned above the varying 



