64 PRACTICAL PARASITOLOGY 



demonstration. We shall, for this reason, omit any description of the 

 complicated developmental stages which take place within the 

 stomach of the mosquito. It is sufficient for the present purpose to 

 state that the ookinets speedily develop flagella and assume the 

 typical Trypanosome form. 



According to Hartrnann, H. noctuce may be cultivated similarly 

 to T. lewisi upon blood-agar (p. 59). In the first twenty-four hours, 

 single ookinets appear in the cultures. In the next few days, flagellate 

 forms appear, similar to those in the gut of the Culex. 



Note : Leucocytozoon ziemanni. 



When examining the blood of owls or other birds of prey for 

 Hczmoproteus, it is by no means unusual to come upon the sex-forms 

 of L. ziemanni. In a pale spindle-shaped envelope, which corre- 

 sponds to the modified periblast, and which is of about the same length 

 as a red blood corpuscle, lies an oval plasmic body, which exhibits 

 the same dimorphism in regard to structure of the plasm and nuclear 

 conditions as the sex-forms of Hcemoproteus. In its immediate 

 vicinity is seen the nucleus of a red corpuscle, deformed to a dumb- 

 bell shape by the depredations of the parasite. The parasite is of 

 comparatively .large size, and for this reason the eight double nuclei 

 in the microgamete stage are more easily recognized than in 

 Hcemoproteus. 



(c) Babesia. 



The theoretic value of Babesia approximates to that of Hczmo- 

 proteus, while its practical importance is considerable. Unfortunately, 

 fresh material is difficult to obtain, but blood smears containing 

 Babesia canis should be procured if in any way possible, as their 

 examination is very instructive. The parasites will be found occupy- 

 ing the red corpuscles, and their nuclear structure should be carefully 

 studied. Although the flagella are absent, two nuclei are present, as 

 in the Trypanosomes. The larger or principal nucleus stains pink 

 with Bomanowsky, while the smaller or flagellar nucleus takes on a 

 more violent tone. The latter is readily discernible, as it is placed 

 close to the pointed end of the more or less pear-shaped parasite. The 

 formation of a flagellum from this nucleus has been observed only 

 in cultures upon artificial media. 



(d) Plasmodia. 



Opportunities of examining the malaria parasite in the living state 

 are rare in this country, but cover-glass specimens may sometimes be 

 obtained. Multiplication by schizogony is usually synchronous in 



