THE MICROSCOPE. 



from the mesentery to show capillaries containing blood elements. 

 Fortunately, however, for our purpose, the blood corpuscles in the 

 capillaries show a number of the same parasites seen on the slide 

 just mentioned. Both the preparations from the mesentery and the 

 slide with blood were exhibited at a meeting of the Richmond 

 Microscopical Society. 



There are two forms of this worm-like parasite seen on the 

 slide: the one, which we consider the immature form, is by far the 

 most numerous and is invariably in connection with the blood cor- 

 puscles (Figures 3, 5, 6, 7, 8, 9, io)-. There is a difference of opinion 

 between us: one of us believing that some of these parasites are 

 within the blood corpuscle, while the other is of the opinion that 

 they are invariably on the outside. Those which are on the outside, 

 about which we both agree, are figured in Nos. 4, 8, 9 and 10. 



The mature form is always seen free among the blood corpus- 

 cles (Figures 1 and 2), and is comparatively scarce. We have been 

 unable to trace the exact transition from the one form to the other. 

 The immature form is invariably curved and sometimes adhering 

 only by its two ends to the corpuscles, leaving the central portion 

 unattached, as seen in Fig. 8, where another corpuscle has wedged 

 itself between the worm and the corpuscle to which it is attached. 



The nuclei of the corpuscles which are- infested with these 

 parasites have invariably an eccentric displacement. 



On the concave surface of the worm the staining shows a darkish 

 line, as seen in Figures 3, 5 and 6. 



There are a few instances where the corpuscles have two para- 

 sites, as in Fig. 7. 



In Fig. 4 one of the immature forms adheres to the corpuscle 

 only by one of its extremities, the other floating free. 



We would especially call attention to Figures 9 and 10. In Fig. 

 9 the surface of the corpuscle is wrinkled and puckered by one 

 extremity of the worm apparently attempting to enter the corpuscle. 

 No. 10 shows the completion of the act commenced by No. 9. 

 Here the worm has torn and entered the corpuscle. The wrink- 

 ling in No. 9 and the ragged torn edge in No. 10 indicate clearly 

 to our mind that the corpuscles have a distinct envelope. We are 

 perfectly aware that we are treading upon disputed ground, and we 

 would have some hesitation in expressing ourselves in so decided a 

 manner if we had not the authority of Ranvier, who has clearly 



