CH. II ON BOABD H.M.S. 'FLYING FISH' 31 



actually to have transferred the chief part of its respiratory 

 functions from its gills to its tail. It is a well-known and 

 generally recognised fact, however, that in all the Amphibia 

 the skin plays a very important part as an organ of respira- 

 tion, and it is quite possible that the thin skin between the 

 fin-rays of many fishes also acts as an accessory to the 

 gills and performs the same function. If this is proved 

 to be the case we should have to look upon the taU of Peri- 

 ophthalmus as an example of an organ discharging a 

 function which is performed in a lesser degree by the tails 

 of many if not of all fishes. 



Perhaps the most extraordinary feature of Perioph- 

 thalmus is the curious pair of goggle-eyes. They stand up 

 out of their sockets in a very uncouth manner, and are 

 capable of very extensive rotatory movements. I have 

 examined the anatomy of these eyes in some detail, and 

 can say they are, in accordance with their supra-aquatic 

 existence, more hke the eyes of frogs than of ordinary 

 fishes. 



Periophthalmuses feed upon small crabs and other 

 Crustacea, but I have also frequently found in their stomachs 

 flies and mosquitoes. 



From the fact that they live almost invariably upon 

 uneven, broken ground, and are extremely active and shy, 

 they are exceedingly difficult to catch, and I may as well 

 acknowledge that on this the first day of my acquaintance 

 with them I failed to make a single capture. 



Some weeks afterwards, when I was at work in Talisse, 

 I tried again. The butterfly-net method failed, however, 

 and so did my attempt to catch them fly-fishing, and at 

 last I was obliged to say to my boy severely, ' Go, Manuel 

 and catch me fifty ikan chicchak,' as the natives call them. 

 ' Tida boleh tuan ' (' It can't be done, sir '), replied Manuel 

 who had been an eye-witness of all my failures ; and there- 



