60 PROPESSOR E. RAY LANKESTER. 



falciform corpuscles which are described as occurring within the 

 spores of a very remarkable Sporozoon — the Sarcocystis Mies- 

 cheri. This organism occurs as a cell-parasite within the striated 

 muscular fibres of such animals as the Pig^ Sheep, and Man, and 

 was first described by Miescher, and afterwards (in 1857) by the 

 English anatomist, E-ainey. E.ainey supposed that it was con- 

 nected with the life-cycle of Taenia and Cysticercus. His views 

 as to its significance have been shown to be erroneous, but the 

 parasite has been studied in detail since by other observers, and 

 the correctness of his fundamental observations established. 

 Manz (' Archiv fiir mikr. Anat.,' 1867, Bd. iii) has given 

 figures of the structure of E-ainey's parasite, which attracted 

 some attention in this country at the time of the severe outbreak 

 of cattle plague in 1865, when it was, so to speak, rediscovered 

 by the pathologists who applied themselves to the examination of 

 the meat furnished by diseased cattle. By some writers at that 

 date it was supposed that this organism had a causal relation to the 

 cattle-plague ! (See this Journal, vol. vi, New Series, 1866, p. 96.) 

 I have here reproduced a woodcut (fig. 2 a, b) from Leuckart's 

 work, ' Die Parasiten des Menschen,^ in order to show the close 

 resemblance of the falciform corpuscles of what I propose to call 

 "Sarcocystis Miescheri''^ with the JDrepan'ul'mm ranarum. The 

 corpuscles are produced in the interior of naked irregular masses 

 (spores), which constitute the contents of the oblong sacs with 

 striated cuticle described by Miescher and Rainey. 



Brepanidiiim is not homogeneous in substance. It presents in 

 the living state three bands of differing refractive power, two of 

 higher refractive power placed at the poles of the elongated body 

 and separated by one of less refractive power. When treated 

 with solution of iodine in potassium iodide, the cause of this 

 appearance is seen to be the presence of a strongly refractive oval 

 or rounded particle near each pole of the minute organism (see 

 woodcut, fig. 1). A similar pair of refractive granules are seen 

 in the falciform corpuscles produced in the spores of Sarcocystis 

 (see fig. 2 b). 



I conclude accordingly — 



1st. That JDrepanicUum ranarum is a parasitic organism. 



2nd. That it is probably the young stage of a Sporozoon 

 allied to Sarcocystis or to Coccidium. 



3rd. That researches should be directed to the discovery of 

 a Gregariniform stage, and of cysts containing spores, or of 

 isolated spores in which several Drepanidia may be enclosed. 



These phases in the life-history of Brepanidium are very 

 possibly to be met with in other regions of the Frog's body 

 than the blood-vessels or the spleen. 



Probable Coccidium-phase and Naviculoid Spores of Brepani- 



