ON DREPANIDIUM RANARUM. 53 



On Drepanidium ranarum, the Cell-parasite of the Frog's 

 Blood and Spleen (Gaule's Wiirmschen). By E. Ray 

 Lankestbr, M.A., E.R.S., Jodrell Professor of Zoology in 

 University College, London. 



In the year 1871 I described and figured in this Journal 

 (vol. xi, p. 389), certain minute sausage-like parasites which I 

 had found in the blood of Rana escidenta. I showed that 

 these parasites were sometimes to be met with attached by one 

 end to a red blood-corpuscle, and I exhibited in my drawing 

 of them (here reproduced, figs. 3 and 4), the sharply pointed 

 character of one end of the cylindrical body, the dififerentiation 

 of their substance into bands of greater and less refringency, and 

 the definite curvature of the sausage-like form which they 

 present. I suggested that these parasites were possibly con- 

 nected with the life-history of the Trypanosoma sanguinis of 

 Gruby, which I had observed and supposed to be an unde- 

 scribed organism. At the same time I pointed out their resem- 

 blance to certain peculiar spores which I had observed in the 

 cysts of a Gregarina parasitic in Tubifex. These parasites have, 

 after a lapse of ten years, been re-discovered by Dr. Gaule, 

 whilst working in the Physiological Institute of Professor 

 Ludwig at Leipzig, where I had originally observed them. Dr. 

 Gaule has published two lengthy papers upon them in the 

 * Archiv fiir Physiologic,' 1880 and 1881. In the first of these 

 papers he gave no figure of the object which he was describing, 

 nor did he refer to the fact that it Mas already known. This 

 omission, together with the exceedingly original views which 

 Dr. Gaule advanced as to the nature of the parasites, led to a 

 complete misunderstanding of his observations, so that it was 

 supposed that he had been studying one of those curious phe- 

 nomena of disintegration of the red blood-corpuscle which, 

 from the date of Addison's paper in this Journal (1861) to the 

 present day, have much occupied the attention of histologists. 

 Misled in this manner by the absence of drawings from Dr. 

 Gaule's paper, and by the strange method of reasoning charac- 

 teristic of that observer, Mr. Dowdeswell reported upon these 

 so-called " Wiirmschen " in this Journal, January, 1881, p. 160, 

 and referred the bodies described by Gaule to the category of 

 disintegration products. 



It is now, however, evident from Dr. Gaule's second paper, 

 which is accompanied by a plate, that his " Wiirmschen " are 

 the parasites described by me, a fact which he has become 

 aware of himself. 



