THE CHROMATIN MASSES OF PIROPLASMA BIGEMINUM. 301 



was really seen by Smith and Kilborne, for on page 215 of 

 their raonograpli they remark, regarding fresh specimens, 

 that: "The smaller forms [of the parasite] are as a rule 

 homogeneous ; the larger forms are very frequently observed 

 to be provided, in the rounded end of the pyriform body, 

 with a very minute spherical body probably not more than 

 O'l to 02 jw in diameter, which contrasts dark with the body 

 itself .... In the largest pyriform bodies there was seeii 

 in the centre of the enlarged end a somewhat larger round 

 or oval body which seemed to take the place of the smaller 

 body or else be associated with it. This second body was 

 from 0'5 to 1 fi in diameter. It changed its appearance with 

 the focus .... One or both of these bodies were observed 

 in some of those forms undergoing amceboid changes." 

 Judging by the latter part of this quotation Smith and 

 Kilborne even may have seen " nuclear dimorphism " in 

 parasites occurring " in fresh blood of the acute disease 

 during life." 



Laveran and Nicolle, apparently, were the first definitely to 

 describe and figure^ the nucleus of P. bigeminum in 

 1899 (3), from stained specimens treated with Bori'el blue 

 and eosin, according to Laveran's modification of the 

 Romauowsky method, after fixation by heat and corrosive 

 sublimate. In twin intra-corpuscular forms they found a 

 spherical or oval karyosome at the blunt end of the parasite, 

 measuring 0"7/x to 0"9 ju in diameter, with a clear zone sur- 

 rounding the karyosome, which clear area they regarded as 

 the peripheral part of the nucleus. Laveran and Nicolle also 

 mention the frequent presence of numerous, easily stained 

 granules at the pointed extremity of the parasite. These 

 granules, they state, might easily be mistaken for a second 

 karyosome in deeply stained specimens, but, on decolourising 

 a little, are seen to be really only " agglomerations of 

 granules." Personally, I consider that at the pointed end of 

 the parasite loose chromatin is not infrequently seen (see 

 p. 303). 



' Tliese figures are reproduced iu Mincliiu's ' Sporozoa' (7), p. 269, fig. 80. 



