100 CURIOUS INSTANCES OF PARASITISM IN THE TOAD. 



letter, my correspondent was kind enough to furnish me with some addi- 

 tional particulars. Writing at the close of the year, he observes : — " On 

 examining the toad more carefully, I found each nostril filled with 

 whitish small worm-like bodies, which would amount, I should say, to 

 fifty or more in each nostril. They kept appearing at the outside of the 

 nostrils, and then receding, these movements being probably due to the 

 respiratory efforts of the toad. They also had a rolling motion, indi- 

 vidually. After some hours the septum between the nostrils was quite 

 eaten away, and a large hole appeared in the animal's head, the toad 

 being then quite dead." Dr. McMunn did not observe any rings or 

 hooks, but in a postscript he expresses the opinion that the parasites 

 represented "the larva? of some insect." 



I must here mention that the envelope and box had arrived in a torn 

 state. When I examined the contents of the box, there was nothing but 

 the skeleton of the toad, the remains of numerous pupae, from which the 

 perfect insects had escaped, and the wool and notepaper in which the 

 toad was packed. The surface of the writing paper was plainly marked 

 with impressions of the smooth-skinned pupae. These are distinctly 

 ringed, and when magn'fied about 41 diamet ts show a large number of 

 minute spines. From a sketch suppliel by Dr. McMunn, the living larvae 

 would appear to have been fully a quarter of an inch in length. I found 

 that one of the dried, shrivelled, and empty pupae skins measured exactly 

 one-fifth of an inch in length. The remains of a rather small beetle 

 that had evidently gained access to the box were found lodged in the 

 skeleton. This had certainly nothing to do with the parasitism, about 

 which not a shadow of doubt could exist. In determining the species, 

 I stood in need of the assistance of learned Entomologists ; and it was 

 this which induced me to submit the facts and specimens to the notice of 

 the club. 



Appendix. — During the discussion which followed the reading of this 

 short paper, (in which discussion Messrs. Sheppard, Lowne, Dallas, 

 Pascoe, and the Rev. G. Henslow took part,) Mr. Robert McLachlan, 

 F.R.S., drew attention to recent notices in the " Zoological Record" for 

 1877-78, and he stated that not improbably the larvaB in question 

 would be found to belong to the genus Batrachomyia of MacLeay. In 

 the reports in question I find that reference is made by Mr. E. C. 

 Rye to a note by Herr Boie, on the larvae of a Dipteron attacking 

 the soft parts of the mouths of toads in Bohemia. M. Girard 

 also gives " instances of Batrachians attacked in a similar manner." 

 Mr. Rye quotes also the opinion of MM. Colin de Plancy and E. Taton, 

 that " the flies (Batrachomyia) attack only sores already existing." It 

 appears that M. Moniez had previously referred some dipterous insects, 

 possessing these habits, to the genus Lucilia, one species of which 

 (L. hominivorax ) proves, as everybody knows, so terrible to the convicts 

 at Cayenne. The new fly, L. bufonivora, Mon., lays its eggs " in the eyes 

 of frogs, and the larvae eat into the living batrachian." Mons. Lelievre 

 refers it to L. regalis or L. illustris, Meig., but the opinion is disputed by 



