[ 357 j 



XI. On Simondsia paradoxa and on its Probable Affinity with Sphseralaria boinbi. By 

 T. Spencer Cobbold, M.D., F.R.S., F.L.S., Correspondent of the Academy of 

 Sciences of Pit iladelplt ia. 



(Plate XXXVII.) 



Read March 15th, 1SS3. 



JLlIIRTY years ago (that is, in March 1852) several examples of a remarkable parasite 

 were discovered by Professor James B. Simonds in the coats of the stomach of a German 

 hog. The "host" died at the Zoological Society's Menagerie, Regent's Park. 



The only notice, hitherto recorded, of the worm occupies a few lines of my intro- 

 ductory treatise published in the autumn of 1801 ('Entozoa,' p. 79). The notice is 

 fragmentary and unaccompanied by any technical description of the worm, which, 

 however, I provisionally named Simondsia paradoxa in honour of the discoverer. It was 

 only at the last moment, when the said treatise was going to press, that the late Principal 

 of the Royal Veterinary College called my attention to his specimens and drawings ; hence 

 the paucity of details, and other deficiencies in the record there given. What, at the time, 

 was regarded as the head of the worm turns out to be its tail ; and the inference which 

 Professor Simonds had drawn respecting the strongyloid character of the parasite proves 

 to be incorrect. In justice to the discoverer, it must nevertheless be said that similar 

 misinterpretations have repeatedly occurred, as, for example, in the case of Rcederer's 

 Trichuris, now universally known as Trichocepladits. 



Shortly after the original notice appeared, the drawings of Simondsia were lost. The 

 illustrations had been executed by a skilled artist, the late Mr. Woodman, under Mr. 

 Simonds's superintendence. Only quite recently, on the occasion of Mr. Simonds 

 retiring from London, the illustrations were found ; and thus at length both the drawings 

 and specimens have become available for establishing the genus on a securer basis. As the 

 specimens are unique and also few in number, I have been reluctant to mutilate them ; 

 but, fortunately, their transparency is such that nearly all the important parts can 

 be seen without dissection. 



Although in 1864 I had only opportunity to make a brief outward examination, 

 enough was seen to justify the employment of a new generic name, whilst the specific 

 title bore reference to the presence of a large spherical and somewhat flattened organ 

 whose significance was altogether paradoxical. The singular development in question 

 many times exceeds in size all the rest of the parasite, its diameter being fifteen times 

 that of the body of the worm at its centre (PI. XXXVII. figs. 1 & 2). In the original 

 notice this organ was described as consisting of " special folds of integument formed 

 for the lodgement of unusually developed uterine organs ;" but there is here a false 

 interpretation. At the time this conclusion was formed I had not examined the organ 

 microscopically, neither had helminthologists been made acquainted with Schneider's 



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