The Zoologist— September, 1869. 1831 



prepared to believe. Next we have the following note by Mr. Char- 

 nock in the ' Zoologist' for 1845, at p. 1138. 



" I observed a toad, about a week ago, in the evening after a shower 

 of rain, crawling across a public road, which apparently had a white 

 mark or patch across its back. On examining it closely, I found this 

 occasioned by a large quantity of the eggs of one of the flesh flies 

 being deposited on its back. Is this one of the means employed to 

 keep these reptiles in check } I have never heard of it before : the 

 toad seemed quite lively and in no way injured." 



And again, at page 1215 in the volume for 1846, we have the 

 following details from the pen of an excellent observer, Mr. Chennell, 

 of Guildford :— 



" Last summer, 1845, having noticed a great quantity of dead toads, 

 I was induced to inquire the cause of their death. On the 23rd of 

 August I selected one that seemed unusually inactive: all that I could 

 then see of the disease, after a careful examination, was that one 

 nostril was a little enlarged. I placed the toad in a box inaccessible 

 to small insects, and on opening the box three days afterwards I 

 found the frontal sinuses and fleshy parts of the head devoured by 

 larvae of the flesh fly : after eating the whole of the toad, excepting 

 the skin and bones, they changed into the chrysalis state. 1 did not 

 count the larvse, but 1 should say they numbered a hundred." 



Little as we find published on this subject, there is no fact in 

 natural history more clearly established than this of the Dipteia ovi- 

 positing on the bodies of various species of toads and frogs, with a 

 view to making the softer parts of the body form a pabulum for the 

 future larvae. One of these has been so thoroughly studied in Australia, 

 and is in itself so interesting, that 1 think it unnecessary to make any 

 apology for transferring to the ' Zoologist' an extract from Mr. KrefTt's 

 paper, published in the ' Transactions of the Entomological Society of 

 New South Wales.' 



'* In the course of ray inquiries," says Mr. Kreff't, " into the batra- 

 chian fauna of Australia, I have frequently captured frogs infested 

 with a number of parasites seeming to be the larvae of dipterous 

 insects ; they are generally found between the skin and flesh, just 

 behind the tympanum, but in cases where three or four exist upon a 

 single individual they reach as far back as the anus : these larvae 

 may be taken for glands at first sight, but closer examination soon 

 reveals a small opening, and a gentle pressure will quickly exhume 

 the yellow parasite. In all cases where the larva was forcibly ejected, 



