1911.] NATURAL SCIENCES OF PHILADELPHIA. 459 



2. Thionin and acid fuchsin. 



3. Wright's stain. 



The two former were used in the usual way. With Wright's stain r 

 the conventional procedure was slightly varied. The smear, kept 

 in absolute ethyl alcohol, was first washed in absolute methyl alcohol. 

 It was then stained in the usual way, but after being washed in water,, 

 it was dehydrated with alcohol and transferred to oil. It could 

 therefore be brought into balsam without ever becoming dry. 



The material for paraffin sections was fixed in Hermann's fluid. 



Observations. 

 Fresh Material. 



The Cysts. — As already stated, the cysts were mostly aggregated 

 in that portion of the muscle lying beneath the skin. As is usual with 

 Sarcosporidia, their long axes lay in the same direction as the long 

 axes of the muscle fibres. Stretching of the muscle caused the cysts 

 to lengthen and become narrower, they being in all cases very soft 

 and flexible. They were very easily teased out from the surrounding- 

 host tissue, and could be obtained free of all such tissue and wholly 

 intact without the least difficulty. 



Both in situ and when free on the slide, the form was that of a 

 cylinder with rounded ends. That is, the diameter was sensibly 

 uniform throughout, although, when the muscle surrounding a cyst 

 was stretched, the cyst became somewhat narrower at the ends. 



The length varied from 2.75-6.5 mm.; the diameter from .6-1.0 

 mm. There was, however, no constant relation between length and 

 thickness, and indeed the shorter cysts were frequently the thicker. 

 Four, selected at random, and measured while in position, gave the 

 following : 



6.0 by .60 mm. 



5.5 by .75 mm. 



4.0 by 1.00 mm. 



6.5 by .60 mm. 



It is probable that the ratio of length and breadth depends a good 

 deal on the pressure exerted on the cyst by the surrounding tissue. 

 Obviously, also, in the living bird, the parasites are subjected to very 

 violent stresses and strains. 



The Spores. — Preparations made by teasing the cysts in salt solution 

 were examined under the microscope. The spores varied a good deal 

 in size and shape. Some were short, broad ovals, others had somewhat 



