214 NOTES AND MEMOEANDA. 



thus used, but these various substances are nearly always symmetri- 

 cally placed on corresponding parts of the body, and particularly long 

 plume-like pieces are fixed on the head, sticking up from it. It may 

 be supposed that these actions are of use for purposes of concealment, 

 and hence it might be expected that they should be dependent on the 

 power of vision, but not only are all these complicated processes gone 

 through at night as well as by day, but a Stenorhynchus if cleaned 

 and deprived of sight will immediately begin to clothe itself again 

 with the same care and precision as before. It may be mentioned 

 that there is certainly no disposition on the part of a Stenorhynchus 

 dressed in any colour, say green, to take up a position amongst 

 green weed or indeed amongst weed at all, and so on, while some 

 individuals which have taken up their station among weeds do not 

 dress themselves at all. 



Sense of Touch in the Rockling [Motella). — Both the large three- 

 bearded rockling and the small five- bearded form flourish in the 

 tanks. They are nocturnal in their habits, and lie still all day. 

 If a worm be thrown in by day, the small species will sometimes 

 swim straight up and take it, having to some extent the power of 

 seeing objects, but the large species never does this. Generally, 

 both the animals take no notice of food thrown in until it has lain 

 in the water some minutes, when they start off in search of it. 

 The rockling searches by setting its filamentous pelvic fins at right 

 angles to the body, and then swimming about feeliug with them. 

 If the fins touch a piece of fish or other soft body, the rockling 

 turns its head round and snaps it up with great quickness. It will 

 even turn round and examine uneatable substances, as glass, &c., 

 which come in contact with its fins, and which presumably seem to 

 it to require explanation. The recklings have great powers of 

 scent and will set off in search of meat hidden in a bottle sunk in the 

 water. Moreover, a blind rockling will hunt for its food and find 

 it as easily as an uninjured one. 



The barbels of the recklings bear sense organs having the 

 structure of taste-bulbs, but the sensitive rays of the pelvic fins do 

 not, having an epithelium made of tall, thin cells, somewhat like 

 that upon the fingers of a gurnard. 



Sudden Colour Changes in Conger. — During the months of May, June, 

 and July I occasionally saw the conger living in the tanks more or 

 less covered with bright, white spots. These spots come and go 

 suddenly, and their size varies from that of small shot to that of a 

 threepenny-piece. Sometimes the head, both sides of the pectoral 

 and dorsal fins, and anterior end are thus covered, while sometimes 



